✓ Editorially reviewed by Derek Giordano, Founder & Editor · BA Business Marketing

Time Card Calculator

Hours, Overtime & Pay

Last reviewed: May 2026

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Time Card Calculator

Calculate hours worked, overtime, and gross pay from clock-in and clock-out times. Converting between clock times (8:45 AM), decimal hours (8.75), and payroll calculations is error-prone by hand — especially with overtime rules, split shifts, and varying break lengths. This tool handles all conversions and applies overtime rules automatically.1

Minutes to Decimal Conversion

MinutesDecimalMinutesDecimal
50.08350.58
100.17400.67
150.25450.75
200.33500.83
250.42550.92
300.50601.00

Overtime Rules by Type

RuleThresholdRateWhere
Federal weekly>40 hrs/week1.5×All states
CA daily>8 hrs/day1.5×California
CA double-time>12 hrs/dayCalifornia
7th consecutive dayAny hours1.5×Some states

How Time Card Calculations Work

Time card math converts clock-in and clock-out times to decimal hours for payroll calculation. The key conversion: minutes to decimal hours by dividing by 60. Clocking in at 8:15 AM and out at 5:45 PM: 5:45 PM = 17:45 in 24-hour format. Total time: 17.75 - 8.25 = 9.50 hours. Subtract a 30-minute unpaid lunch: 9.50 - 0.50 = 9.00 billable hours. Common time-to-decimal conversions: 15 minutes = 0.25, 30 minutes = 0.50, 45 minutes = 0.75. Less intuitive: 10 minutes = 0.17, 20 minutes = 0.33, 40 minutes = 0.67. Many payroll systems round to the nearest quarter-hour (7-minute rule): clocking in at 8:07 rounds to 8:00, while 8:08 rounds to 8:15. This rounding is legal under the FLSA as long as it doesn't systematically favor the employer over time — it should roughly balance between rounding up and rounding down across pay periods.

Overtime Calculation Rules

Federal law (FLSA) requires overtime pay at 1.5× the regular rate for hours exceeding 40 in a workweek. The workweek is any fixed, recurring 168-hour period defined by the employer — it doesn't have to be Monday through Sunday. If you work 45 hours in a workweek at $20/hour: 40 hours × $20 = $800 regular pay, plus 5 hours × $30 (time-and-a-half) = $150 overtime. Total: $950. Some states add daily overtime: California requires time-and-a-half after 8 hours in any single day and double time after 12 hours, regardless of weekly total. This means a California employee working four 12-hour days (48 hours) earns overtime for 16 hours (4 hours × 4 days of daily overtime) even though 48 hours would only trigger 8 hours of overtime under federal rules. For employees with multiple pay rates (working different positions for the same employer), overtime uses the weighted average of all rates worked that week, not the rate of the position worked during the overtime hours.

Common Payroll Mistakes and Disputes

Time card errors cost employees and employers billions annually. The most common employee error: forgetting to clock in or out, requiring manual time entry that may be rounded unfavorably. The most common employer error: not paying for "off-the-clock" work — time spent booting up computers, putting on required safety gear, or attending mandatory meetings before the official shift starts is compensable time under federal law. Working through lunch without clocking the meal break is another frequent issue: if you eat at your desk while answering emails, that's a working lunch and should be paid, regardless of company policy designating it as a break. Misclassifying employees as exempt (salaried, no overtime) when their duties don't meet the FLSA duties test results in back-pay claims averaging $2,000-5,000 per employee per year of misclassification. Keep personal records of your work hours independently of your employer's system — in disputes, contemporaneous time records carry significant legal weight.

Shift Differentials and Premium Pay

Many employers pay premium rates for less desirable shifts. Second shift (typically 3-11 PM) often receives a 5-10% differential: $20/hour base becomes $21-22/hour. Third shift (11 PM - 7 AM) may receive 10-15%: $20 becomes $22-23/hour. Weekend differentials of 10-25% compensate for working non-standard days. Holiday premium pay (often double time) applies to designated holidays. These differentials interact with overtime calculations: when a shift differential applies, the increased rate must be included in the regular rate calculation for overtime purposes. If your base rate is $20 with a $2 shift differential, overtime is based on $22/hour, making overtime pay $33/hour — not $30 (which would be 1.5× the base without differential). This distinction frequently results in underpayment that employees don't notice and employers may not intentionally cause but are legally obligated to correct.

Time Tracking Best Practices

Whether you're an employee tracking hours or an employer managing payroll, consistent time tracking prevents disputes and ensures accurate compensation. Digital time clocks with biometric (fingerprint or facial recognition) authentication eliminate buddy punching — where one employee clocks in for another — estimated to cost employers 2-5% of gross payroll. Mobile time tracking apps (Toggl, Clockify, Harvest) work well for remote and field employees, using GPS to verify location. For freelancers and contractors, detailed time tracking supports invoicing accuracy and provides documentation if clients dispute bills. Track time in real-time rather than reconstructing at the end of the week: research shows that delayed time entry underestimates actual hours worked by 10-15%, effectively giving away unpaid labor. Break times should be explicitly tracked: short breaks (under 20 minutes) are compensable under FLSA, while meal breaks (30+ minutes with complete relief from duties) are not.

Calculate hours worked?
Clock-out minus clock-in minus breaks. 8:00 AM to 5:00 PM with 30 min lunch = 8.5 hours.

How Time Card Calculations Work

Time card math converts clock-in and clock-out times to decimal hours for payroll calculation. The key conversion: minutes to decimal hours by dividing by 60. Clocking in at 8:15 AM and out at 5:45 PM: 5:45 PM = 17:45 in 24-hour format. Total time: 17.75 - 8.25 = 9.50 hours. Subtract a 30-minute unpaid lunch: 9.50 - 0.50 = 9.00 billable hours. Common time-to-decimal conversions: 15 minutes = 0.25, 30 minutes = 0.50, 45 minutes = 0.75. Less intuitive: 10 minutes = 0.17, 20 minutes = 0.33, 40 minutes = 0.67. Many payroll systems round to the nearest quarter-hour (7-minute rule): clocking in at 8:07 rounds to 8:00, while 8:08 rounds to 8:15. This rounding is legal under the FLSA as long as it doesn't systematically favor the employer over time — it should roughly balance between rounding up and rounding down across pay periods.

Overtime Calculation Rules

Federal law (FLSA) requires overtime pay at 1.5× the regular rate for hours exceeding 40 in a workweek. The workweek is any fixed, recurring 168-hour period defined by the employer — it doesn't have to be Monday through Sunday. If you work 45 hours in a workweek at $20/hour: 40 hours × $20 = $800 regular pay, plus 5 hours × $30 (time-and-a-half) = $150 overtime. Total: $950. Some states add daily overtime: California requires time-and-a-half after 8 hours in any single day and double time after 12 hours, regardless of weekly total. This means a California employee working four 12-hour days (48 hours) earns overtime for 16 hours (4 hours × 4 days of daily overtime) even though 48 hours would only trigger 8 hours of overtime under federal rules. For employees with multiple pay rates (working different positions for the same employer), overtime uses the weighted average of all rates worked that week, not the rate of the position worked during the overtime hours.

Common Payroll Mistakes and Disputes

Time card errors cost employees and employers billions annually. The most common employee error: forgetting to clock in or out, requiring manual time entry that may be rounded unfavorably. The most common employer error: not paying for "off-the-clock" work — time spent booting up computers, putting on required safety gear, or attending mandatory meetings before the official shift starts is compensable time under federal law. Working through lunch without clocking the meal break is another frequent issue: if you eat at your desk while answering emails, that's a working lunch and should be paid, regardless of company policy designating it as a break. Misclassifying employees as exempt (salaried, no overtime) when their duties don't meet the FLSA duties test results in back-pay claims averaging $2,000-5,000 per employee per year of misclassification. Keep personal records of your work hours independently of your employer's system — in disputes, contemporaneous time records carry significant legal weight.

Shift Differentials and Premium Pay

Many employers pay premium rates for less desirable shifts. Second shift (typically 3-11 PM) often receives a 5-10% differential: $20/hour base becomes $21-22/hour. Third shift (11 PM - 7 AM) may receive 10-15%: $20 becomes $22-23/hour. Weekend differentials of 10-25% compensate for working non-standard days. Holiday premium pay (often double time) applies to designated holidays. These differentials interact with overtime calculations: when a shift differential applies, the increased rate must be included in the regular rate calculation for overtime purposes. If your base rate is $20 with a $2 shift differential, overtime is based on $22/hour, making overtime pay $33/hour — not $30 (which would be 1.5× the base without differential). This distinction frequently results in underpayment that employees don't notice and employers may not intentionally cause but are legally obligated to correct.

Time Tracking Best Practices

Whether you're an employee tracking hours or an employer managing payroll, consistent time tracking prevents disputes and ensures accurate compensation. Digital time clocks with biometric (fingerprint or facial recognition) authentication eliminate buddy punching — where one employee clocks in for another — estimated to cost employers 2-5% of gross payroll. Mobile time tracking apps (Toggl, Clockify, Harvest) work well for remote and field employees, using GPS to verify location. For freelancers and contractors, detailed time tracking supports invoicing accuracy and provides documentation if clients dispute bills. Track time in real-time rather than reconstructing at the end of the week: research shows that delayed time entry underestimates actual hours worked by 10-15%, effectively giving away unpaid labor. Break times should be explicitly tracked: short breaks (under 20 minutes) are compensable under FLSA, while meal breaks (30+ minutes with complete relief from duties) are not.

Overtime?
Federal: 1.5× over 40 hrs/week. Some states have daily OT (CA: over 8 hrs/day). See our Paycheck Calculator for take-home pay.2

How Time Card Calculations Work

Time card math converts clock-in and clock-out times to decimal hours for payroll calculation. The key conversion: minutes to decimal hours by dividing by 60. Clocking in at 8:15 AM and out at 5:45 PM: 5:45 PM = 17:45 in 24-hour format. Total time: 17.75 - 8.25 = 9.50 hours. Subtract a 30-minute unpaid lunch: 9.50 - 0.50 = 9.00 billable hours. Common time-to-decimal conversions: 15 minutes = 0.25, 30 minutes = 0.50, 45 minutes = 0.75. Less intuitive: 10 minutes = 0.17, 20 minutes = 0.33, 40 minutes = 0.67. Many payroll systems round to the nearest quarter-hour (7-minute rule): clocking in at 8:07 rounds to 8:00, while 8:08 rounds to 8:15. This rounding is legal under the FLSA as long as it doesn't systematically favor the employer over time — it should roughly balance between rounding up and rounding down across pay periods.

Overtime Calculation Rules

Federal law (FLSA) requires overtime pay at 1.5× the regular rate for hours exceeding 40 in a workweek. The workweek is any fixed, recurring 168-hour period defined by the employer — it doesn't have to be Monday through Sunday. If you work 45 hours in a workweek at $20/hour: 40 hours × $20 = $800 regular pay, plus 5 hours × $30 (time-and-a-half) = $150 overtime. Total: $950. Some states add daily overtime: California requires time-and-a-half after 8 hours in any single day and double time after 12 hours, regardless of weekly total. This means a California employee working four 12-hour days (48 hours) earns overtime for 16 hours (4 hours × 4 days of daily overtime) even though 48 hours would only trigger 8 hours of overtime under federal rules. For employees with multiple pay rates (working different positions for the same employer), overtime uses the weighted average of all rates worked that week, not the rate of the position worked during the overtime hours.

Common Payroll Mistakes and Disputes

Time card errors cost employees and employers billions annually. The most common employee error: forgetting to clock in or out, requiring manual time entry that may be rounded unfavorably. The most common employer error: not paying for "off-the-clock" work — time spent booting up computers, putting on required safety gear, or attending mandatory meetings before the official shift starts is compensable time under federal law. Working through lunch without clocking the meal break is another frequent issue: if you eat at your desk while answering emails, that's a working lunch and should be paid, regardless of company policy designating it as a break. Misclassifying employees as exempt (salaried, no overtime) when their duties don't meet the FLSA duties test results in back-pay claims averaging $2,000-5,000 per employee per year of misclassification. Keep personal records of your work hours independently of your employer's system — in disputes, contemporaneous time records carry significant legal weight.

Shift Differentials and Premium Pay

Many employers pay premium rates for less desirable shifts. Second shift (typically 3-11 PM) often receives a 5-10% differential: $20/hour base becomes $21-22/hour. Third shift (11 PM - 7 AM) may receive 10-15%: $20 becomes $22-23/hour. Weekend differentials of 10-25% compensate for working non-standard days. Holiday premium pay (often double time) applies to designated holidays. These differentials interact with overtime calculations: when a shift differential applies, the increased rate must be included in the regular rate calculation for overtime purposes. If your base rate is $20 with a $2 shift differential, overtime is based on $22/hour, making overtime pay $33/hour — not $30 (which would be 1.5× the base without differential). This distinction frequently results in underpayment that employees don't notice and employers may not intentionally cause but are legally obligated to correct.

Time Tracking Best Practices

Whether you're an employee tracking hours or an employer managing payroll, consistent time tracking prevents disputes and ensures accurate compensation. Digital time clocks with biometric (fingerprint or facial recognition) authentication eliminate buddy punching — where one employee clocks in for another — estimated to cost employers 2-5% of gross payroll. Mobile time tracking apps (Toggl, Clockify, Harvest) work well for remote and field employees, using GPS to verify location. For freelancers and contractors, detailed time tracking supports invoicing accuracy and provides documentation if clients dispute bills. Track time in real-time rather than reconstructing at the end of the week: research shows that delayed time entry underestimates actual hours worked by 10-15%, effectively giving away unpaid labor. Break times should be explicitly tracked: short breaks (under 20 minutes) are compensable under FLSA, while meal breaks (30+ minutes with complete relief from duties) are not.

Minutes to decimal?
Divide by 60. 15 min = 0.25, 30 = 0.50, 45 = 0.75. Required for payroll.3

How Time Card Calculations Work

Time card math converts clock-in and clock-out times to decimal hours for payroll calculation. The key conversion: minutes to decimal hours by dividing by 60. Clocking in at 8:15 AM and out at 5:45 PM: 5:45 PM = 17:45 in 24-hour format. Total time: 17.75 - 8.25 = 9.50 hours. Subtract a 30-minute unpaid lunch: 9.50 - 0.50 = 9.00 billable hours. Common time-to-decimal conversions: 15 minutes = 0.25, 30 minutes = 0.50, 45 minutes = 0.75. Less intuitive: 10 minutes = 0.17, 20 minutes = 0.33, 40 minutes = 0.67. Many payroll systems round to the nearest quarter-hour (7-minute rule): clocking in at 8:07 rounds to 8:00, while 8:08 rounds to 8:15. This rounding is legal under the FLSA as long as it doesn't systematically favor the employer over time — it should roughly balance between rounding up and rounding down across pay periods.

Overtime Calculation Rules

Federal law (FLSA) requires overtime pay at 1.5× the regular rate for hours exceeding 40 in a workweek. The workweek is any fixed, recurring 168-hour period defined by the employer — it doesn't have to be Monday through Sunday. If you work 45 hours in a workweek at $20/hour: 40 hours × $20 = $800 regular pay, plus 5 hours × $30 (time-and-a-half) = $150 overtime. Total: $950. Some states add daily overtime: California requires time-and-a-half after 8 hours in any single day and double time after 12 hours, regardless of weekly total. This means a California employee working four 12-hour days (48 hours) earns overtime for 16 hours (4 hours × 4 days of daily overtime) even though 48 hours would only trigger 8 hours of overtime under federal rules. For employees with multiple pay rates (working different positions for the same employer), overtime uses the weighted average of all rates worked that week, not the rate of the position worked during the overtime hours.

Common Payroll Mistakes and Disputes

Time card errors cost employees and employers billions annually. The most common employee error: forgetting to clock in or out, requiring manual time entry that may be rounded unfavorably. The most common employer error: not paying for "off-the-clock" work — time spent booting up computers, putting on required safety gear, or attending mandatory meetings before the official shift starts is compensable time under federal law. Working through lunch without clocking the meal break is another frequent issue: if you eat at your desk while answering emails, that's a working lunch and should be paid, regardless of company policy designating it as a break. Misclassifying employees as exempt (salaried, no overtime) when their duties don't meet the FLSA duties test results in back-pay claims averaging $2,000-5,000 per employee per year of misclassification. Keep personal records of your work hours independently of your employer's system — in disputes, contemporaneous time records carry significant legal weight.

Shift Differentials and Premium Pay

Many employers pay premium rates for less desirable shifts. Second shift (typically 3-11 PM) often receives a 5-10% differential: $20/hour base becomes $21-22/hour. Third shift (11 PM - 7 AM) may receive 10-15%: $20 becomes $22-23/hour. Weekend differentials of 10-25% compensate for working non-standard days. Holiday premium pay (often double time) applies to designated holidays. These differentials interact with overtime calculations: when a shift differential applies, the increased rate must be included in the regular rate calculation for overtime purposes. If your base rate is $20 with a $2 shift differential, overtime is based on $22/hour, making overtime pay $33/hour — not $30 (which would be 1.5× the base without differential). This distinction frequently results in underpayment that employees don't notice and employers may not intentionally cause but are legally obligated to correct.

Time Tracking Best Practices

Whether you're an employee tracking hours or an employer managing payroll, consistent time tracking prevents disputes and ensures accurate compensation. Digital time clocks with biometric (fingerprint or facial recognition) authentication eliminate buddy punching — where one employee clocks in for another — estimated to cost employers 2-5% of gross payroll. Mobile time tracking apps (Toggl, Clockify, Harvest) work well for remote and field employees, using GPS to verify location. For freelancers and contractors, detailed time tracking supports invoicing accuracy and provides documentation if clients dispute bills. Track time in real-time rather than reconstructing at the end of the week: research shows that delayed time entry underestimates actual hours worked by 10-15%, effectively giving away unpaid labor. Break times should be explicitly tracked: short breaks (under 20 minutes) are compensable under FLSA, while meal breaks (30+ minutes with complete relief from duties) are not.

Breaks paid?
Under 20 min: typically paid. 30+ min meals: unpaid if fully relieved. State laws vary.

How Time Card Calculations Work

Time card math converts clock-in and clock-out times to decimal hours for payroll calculation. The key conversion: minutes to decimal hours by dividing by 60. Clocking in at 8:15 AM and out at 5:45 PM: 5:45 PM = 17:45 in 24-hour format. Total time: 17.75 - 8.25 = 9.50 hours. Subtract a 30-minute unpaid lunch: 9.50 - 0.50 = 9.00 billable hours. Common time-to-decimal conversions: 15 minutes = 0.25, 30 minutes = 0.50, 45 minutes = 0.75. Less intuitive: 10 minutes = 0.17, 20 minutes = 0.33, 40 minutes = 0.67. Many payroll systems round to the nearest quarter-hour (7-minute rule): clocking in at 8:07 rounds to 8:00, while 8:08 rounds to 8:15. This rounding is legal under the FLSA as long as it doesn't systematically favor the employer over time — it should roughly balance between rounding up and rounding down across pay periods.

Overtime Calculation Rules

Federal law (FLSA) requires overtime pay at 1.5× the regular rate for hours exceeding 40 in a workweek. The workweek is any fixed, recurring 168-hour period defined by the employer — it doesn't have to be Monday through Sunday. If you work 45 hours in a workweek at $20/hour: 40 hours × $20 = $800 regular pay, plus 5 hours × $30 (time-and-a-half) = $150 overtime. Total: $950. Some states add daily overtime: California requires time-and-a-half after 8 hours in any single day and double time after 12 hours, regardless of weekly total. This means a California employee working four 12-hour days (48 hours) earns overtime for 16 hours (4 hours × 4 days of daily overtime) even though 48 hours would only trigger 8 hours of overtime under federal rules. For employees with multiple pay rates (working different positions for the same employer), overtime uses the weighted average of all rates worked that week, not the rate of the position worked during the overtime hours.

Common Payroll Mistakes and Disputes

Time card errors cost employees and employers billions annually. The most common employee error: forgetting to clock in or out, requiring manual time entry that may be rounded unfavorably. The most common employer error: not paying for "off-the-clock" work — time spent booting up computers, putting on required safety gear, or attending mandatory meetings before the official shift starts is compensable time under federal law. Working through lunch without clocking the meal break is another frequent issue: if you eat at your desk while answering emails, that's a working lunch and should be paid, regardless of company policy designating it as a break. Misclassifying employees as exempt (salaried, no overtime) when their duties don't meet the FLSA duties test results in back-pay claims averaging $2,000-5,000 per employee per year of misclassification. Keep personal records of your work hours independently of your employer's system — in disputes, contemporaneous time records carry significant legal weight.

Shift Differentials and Premium Pay

Many employers pay premium rates for less desirable shifts. Second shift (typically 3-11 PM) often receives a 5-10% differential: $20/hour base becomes $21-22/hour. Third shift (11 PM - 7 AM) may receive 10-15%: $20 becomes $22-23/hour. Weekend differentials of 10-25% compensate for working non-standard days. Holiday premium pay (often double time) applies to designated holidays. These differentials interact with overtime calculations: when a shift differential applies, the increased rate must be included in the regular rate calculation for overtime purposes. If your base rate is $20 with a $2 shift differential, overtime is based on $22/hour, making overtime pay $33/hour — not $30 (which would be 1.5× the base without differential). This distinction frequently results in underpayment that employees don't notice and employers may not intentionally cause but are legally obligated to correct.

Time Tracking Best Practices

Whether you're an employee tracking hours or an employer managing payroll, consistent time tracking prevents disputes and ensures accurate compensation. Digital time clocks with biometric (fingerprint or facial recognition) authentication eliminate buddy punching — where one employee clocks in for another — estimated to cost employers 2-5% of gross payroll. Mobile time tracking apps (Toggl, Clockify, Harvest) work well for remote and field employees, using GPS to verify location. For freelancers and contractors, detailed time tracking supports invoicing accuracy and provides documentation if clients dispute bills. Track time in real-time rather than reconstructing at the end of the week: research shows that delayed time entry underestimates actual hours worked by 10-15%, effectively giving away unpaid labor. Break times should be explicitly tracked: short breaks (under 20 minutes) are compensable under FLSA, while meal breaks (30+ minutes with complete relief from duties) are not.

Overnight shifts?
10 PM to 6:30 AM = 8.5 hours. Calculator handles overnight automatically.4

How to Use This Calculator

  1. Enter times — Clock-in, clock-out for each day.
  2. Set breaks — Lunch and other break durations.
  3. Review totals — Daily hours, weekly total, overtime, gross pay.

Tips and Best Practices

Use decimal hours for payroll. 15 min = 0.25, not 0.15.

Track breaks accurately. Short breaks under 20 min are usually paid time.

Know your state rules. CA, CO, and others have daily overtime in addition to federal weekly OT.

Keep records. Federal law requires employers to keep time records for 2 years.

See also: Paycheck · Percentage · Date Difference · Budget

📚 Sources & References
  1. [1] DOL. "FLSA Overtime." DOL.gov. DOL.gov
  2. [2] IRS. "Employment Tax." IRS.gov. IRS.gov
  3. [3] SHRM. "Timekeeping." SHRM.org. SHRM.org
  4. [4] CA DIR. "Overtime." DIR.ca.gov. DIR.ca.gov
Editorial Standards — Every calculator is built from peer-reviewed formulas and official data sources, editorially reviewed for accuracy, and updated regularly. Read our full methodology · About the author