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kWh Cost Calculator

Electricity Cost per Appliance

Last reviewed: April 2026

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What Is a kWh Cost Calculator?

Calculate the electricity cost to run any appliance. Enter wattage, hours of use, and your electric rate to get daily, monthly, and annual costs. This calculator runs entirely in your browser — your data stays private, and no account is required.

How to Calculate Electricity Cost

Every electrical appliance has a wattage rating — the amount of power it draws when running. To find how much it costs to operate, you need three numbers: the appliance's wattage, hours of use per day, and your electricity rate (cost per kilowatt-hour). The formula: kWh = Watts × Hours ÷ 1,000. Then multiply kWh by your rate.

The Formula

Daily cost = (Watts × Hours per day ÷ 1,000) × Rate per kWh

Example: A 1,500-watt space heater running 8 hours per day at $0.16/kWh: (1,500 × 8 ÷ 1,000) × $0.16 = $1.92 per day ($57.60/month). That single heater costs more to run than most people expect.

Average US Electricity Rates

The national average residential rate is approximately $0.16–0.17 per kWh as of 2025. However, rates vary enormously by state: Hawaii: $0.43/kWh. Connecticut: $0.29/kWh. California: $0.27/kWh. Texas: $0.13/kWh. Louisiana: $0.10/kWh. Idaho: $0.09/kWh. Check your electric bill for your exact rate — it's usually listed as "Energy Charge" per kWh.

High-Cost Appliances

Central AC: 3,000–5,000W. At 8 hrs/day = $3.84–6.40/day. Electric water heater: 4,500W but cycles on/off; ~3 hrs active/day = $2.16/day. Space heater: 1,500W × 8 hrs = $1.92/day. Electric dryer: 5,000W × 1 hr = $0.80/load. Refrigerator: 150W but runs ~8 hrs total/day = $0.19/day. LED bulb: 10W × 8 hrs = $0.01/day (essentially free).

Tips to Reduce Electricity Costs

Switch to LED lighting: A 60W-equivalent LED uses only 8–10W — saves $10–15/bulb/year. Use a smart thermostat: Saves 10–15% on heating/cooling. Unplug phantom loads: Devices on standby draw 5–10W each. A power strip with switch eliminates this. Run appliances during off-peak hours: If your utility offers time-of-use rates, shifting dishwasher and laundry to nights saves 20–40%. Upgrade old appliances: A 20-year-old fridge uses 2–3× the electricity of a new Energy Star model.

Cost per kWh by Energy Source

SourceCost/kWhTrend
Grid electricity (U.S. avg)$0.16Rising 2-3%/yr
Residential solar (owned)$0.05–$0.08Declining
Natural gas (heating)$0.03–$0.06Volatile
Gasoline (per kWh equiv)$0.12–$0.15Volatile
EV charging (home)$0.04–$0.06Stable

How Electricity Pricing Works

Electricity is priced in kilowatt-hours (kWh) — one kWh equals the energy consumed by running a 1,000-watt appliance for one hour, or a 100-watt light bulb for 10 hours. The average U.S. residential electricity rate is approximately $0.16-$0.17 per kWh, but rates vary enormously by state: Hawaii leads at $0.40+/kWh due to imported fuel dependence, while states like Idaho, Utah, and Washington benefit from hydroelectric power at $0.10-$0.12/kWh. Electricity bills include several components beyond the per-kWh energy charge: delivery charges (the cost of transmitting power through the grid, often 30-50% of the total bill), demand charges (for commercial and some residential customers, based on peak power draw), fuel adjustment charges (passed through when fuel costs exceed baseline projections), and fixed monthly customer charges ($5-$20 regardless of usage).

Residential Electricity Costs by State

StateAvg. Rate (¢/kWh)Avg. Monthly BillPrimary Source
Hawaii40-44¢$300+Petroleum, solar
Connecticut29-33¢$200-$250Natural gas, nuclear
California28-32¢$180-$250Natural gas, solar, wind
Texas13-17¢$140-$200Natural gas, wind
Florida14-16¢$150-$200Natural gas, solar
Washington10-12¢$90-$120Hydroelectric
Idaho9-11¢$80-$110Hydroelectric

Understanding Your Electricity Bill Structure

Most consumers focus on the per-kWh rate without understanding that their actual cost per kWh consumed is higher when all bill components are included. A bill showing 1,000 kWh of usage at $0.14/kWh ($140 energy charge) plus a $12 customer charge, $45 delivery charge, $8 in taxes and fees, and $5 in renewable energy surcharges totals $210 — an effective rate of $0.21/kWh, 50% higher than the advertised energy rate. Time-of-use (TOU) pricing is becoming standard in many states, charging different rates based on when electricity is consumed: off-peak hours (typically 9pm-7am and weekends) may cost $0.08-$0.12/kWh, while peak hours (typically 2pm-7pm weekdays) may cost $0.30-$0.50/kWh. Shifting high-consumption activities like running the dishwasher, laundry, and electric vehicle charging to off-peak hours can reduce bills by 15-30% under TOU plans.

Reducing Your Electricity Costs

The most cost-effective electricity savings come from addressing the largest energy consumers in your home. Heating and cooling account for approximately 40-50% of residential electricity use — upgrading to a modern heat pump can reduce heating and cooling costs by 30-50% compared to traditional HVAC systems, and many utilities and federal programs offer $2,000-$8,000 in rebates and tax credits for heat pump installation. Water heating accounts for 15-20% of electricity use — heat pump water heaters use 50-70% less electricity than conventional electric water heaters, with payback periods of 2-4 years. LED lighting uses 75% less energy than incandescent bulbs and lasts 15-25 times longer. Smart thermostats save an average of 10-15% on heating and cooling by automatically adjusting temperatures based on occupancy patterns and weather forecasts. Sealing air leaks around windows, doors, and ductwork is often the cheapest improvement — weatherstripping and caulking materials cost $50-$200 and can reduce heating and cooling costs by 10-20%.

Solar, Battery Storage, and Going Off-Grid

Residential solar panels have dropped approximately 70% in cost over the past decade, making solar economically viable in most of the continental United States. A typical 8-10 kW residential solar system costs $16,000-$25,000 before incentives, with the 30% federal Investment Tax Credit reducing the net cost to $11,200-$17,500. In states with strong net metering policies (where the utility credits you at the full retail rate for excess solar production), solar payback periods range from 5-8 years with a system lifespan of 25-30 years. Battery storage systems ($8,000-$15,000 for a 10-13 kWh system) allow homeowners to store excess solar production for use during peak-rate hours or power outages, further reducing grid dependence and electricity costs. For solar ROI calculations, see our Solar Payback Calculator, and for comprehensive energy cost analysis, try our Electricity Cost Calculator.

Commercial and Industrial Electricity Pricing

Commercial electricity pricing is more complex than residential rates, with demand charges often comprising 30-70% of the total bill. Demand charges are based on the highest 15-minute average power draw (measured in kW) during the billing period — a single peak event can set the demand charge for the entire month. A commercial facility with a 200 kW peak demand paying $12/kW in demand charges owes $2,400/month in demand charges alone, regardless of total energy consumption. Reducing peak demand through load management — staggering startup of large equipment, shifting non-critical operations to off-peak hours, and installing demand response systems — often provides greater savings than reducing total energy consumption. Many utilities offer commercial rate classes with lower per-kWh rates for higher-voltage service, interruptible service agreements (lower rates in exchange for allowing the utility to curtail your power during grid emergencies), and economic development rates for qualifying new or expanding businesses.

Smart Home Energy Management

Smart home technology enables granular energy monitoring and automated cost reduction. Smart plugs and energy monitors ($15-$50 each) track consumption by individual device, revealing "phantom loads" — devices that draw power even when turned off, which collectively account for 5-10% of residential electricity use ($50-$150/year). Smart thermostats learn occupancy patterns and automatically adjust temperature settings, saving 10-15% on heating and cooling with typical payback periods under 2 years. Smart power strips automatically cut power to peripheral devices (monitors, speakers, chargers) when the primary device (computer, TV) is turned off. Whole-home energy monitors ($150-$300) connect to the electrical panel and provide real-time consumption data by circuit, identifying which appliances consume the most energy and alerting homeowners to unusual usage patterns that may indicate malfunctioning equipment or energy waste.

How much does it cost to run a space heater?
A typical 1,500W space heater costs about $0.24/hour at the national average rate ($0.16/kWh). Running 8 hours per day: $1.92/day or $57.60/month. In high-rate states like California, that jumps to $3.24/day or $97/month. Central heating is usually cheaper per BTU.
How do I find my electricity rate?
Check your electric bill — look for "Energy Charge" or "Price per kWh." It's usually listed in the rate detail section. The national average is about $0.16/kWh. You can also check your utility's website or call them. Some utilities have tiered rates that increase as you use more.
How much electricity does a refrigerator use?
A modern Energy Star refrigerator uses about 400–600 kWh per year, or roughly $64–96/year at average rates. That's about $5.50–8.00/month. Older refrigerators (15+ years) may use 800–1,200 kWh/year. The fridge is typically the 3rd or 4th largest electricity user in a home after HVAC and water heating. For a related calculation, try our Electricity Bill Calculator.
What is a kilowatt-hour in simple terms?
A kWh is the amount of energy used when a 1,000-watt appliance runs for 1 hour. Equivalently, it is a 100-watt light bulb running for 10 hours, or a 2,000-watt hair dryer running for 30 minutes. Your electricity meter measures cumulative kWh, and you are billed for each kWh consumed. At $0.16/kWh, running a 100W bulb for 10 hours costs about 16 cents.
How can I find my electricity rate?
Check your electric bill — look for the line showing price per kWh or the total kWh used and total charges (divide charges by kWh for your effective rate). Be aware that many utilities have tiered pricing, delivery charges, and fees that make the effective rate higher than the stated rate. Some bills show both generation and delivery charges separately.

See also: Electricity Cost Calculator · Appliance Energy Cost · Solar Payback · Energy Savings · EV vs Gas

How to Use This Calculator

  1. Enter the appliance wattage — Find the wattage on the appliance label, manual, or nameplate. It's usually listed in watts (W) or kilowatts (kW). If only amps and volts are listed, multiply them: watts = amps × volts.
  2. Set hours of daily use — Estimate how many hours per day the appliance runs. A refrigerator runs about 8 hours of compressor time per day; a TV might run 4 hours; a space heater 6–8 hours.
  3. Enter your electricity rate — Input your cost per kWh from your utility bill. The US average is roughly $0.16/kWh, but rates range from $0.10 in Louisiana to $0.45+ in Hawaii. Time-of-use plans have different rates by time of day.
  4. Review daily, monthly, and annual costs — The calculator shows electricity cost for all time periods plus total kWh consumed, helping you identify the most expensive appliances to run.

Tips and Best Practices

Space heaters, AC units, and dryers are the biggest electricity consumers. A 1,500W space heater running 8 hours/day costs ~$55/month at $0.15/kWh. Central AC can cost $100–$200/month. An electric dryer at 5,000W costs about $0.75 per load. Focus efficiency efforts on the biggest energy consumers first. See our Electricity Bill Calculator for whole-house analysis.

Phantom loads (standby power) add up. TVs, game consoles, chargers, and smart devices draw 1–15W even when "off." A house with 20 phantom loads averaging 5W each wastes 100W continuously — that's 876 kWh/year or about $130 at average rates. Smart power strips eliminate phantom loads automatically.

LED bulbs save 75–85% compared to incandescent. A 60W incandescent equivalent LED uses only 8–10W. Replacing 20 bulbs used 5 hours/day saves ~$100/year in electricity. LEDs also last 25,000+ hours vs 1,000 hours for incandescent, eliminating frequent replacement costs.

Time-of-use rates reward shifting heavy usage to off-peak hours. If your utility offers TOU pricing, running the dishwasher, laundry, and EV charging at night (off-peak) can cut those costs by 30–50%. Peak rates (afternoon/evening) can be 2–3× off-peak rates. Model potential savings with our Energy Savings Calculator.

See also: Electricity Bill Calculator · Energy Savings Calculator · Solar Payback Calculator · Appliance Energy Cost Calculator

📚 Sources & References
  1. [1] EIA. Average Retail Price of Electricity. EIA.gov
  2. [2] DOE. Electricity Basics. Energy.gov
  3. [3] NREL. Electricity Cost Data. NREL.gov
  4. [4] ENERGY STAR. Energy Use Calculator. EnergyStar.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