APR, APY & True Cost
Last reviewed: May 2026
Compare interest rates across different products, convert between APR and APY, and calculate the true cost of borrowing or return on savings. The distinction between APR (stated rate) and APY (effective rate including compounding) is the most misunderstood concept in personal finance — banks exploit this by advertising APY on savings and APR on loans.1
| Product | Typical Rate | Type |
|---|---|---|
| 30-year mortgage | 6.5–7.5% | APR |
| 15-year mortgage | 5.8–6.8% | APR |
| Auto loan (new) | 5–8% | APR |
| Personal loan | 8–15% | APR |
| Credit card | 18–28% | APR |
| High-yield savings | 4–5% | APY |
| 1-year CD | 4.5–5% | APY |
| Stated APR | Compounding | Effective APY |
|---|---|---|
| 5% | Annual | 5.00% |
| 5% | Monthly | 5.12% |
| 5% | Daily | 5.13% |
| 18% | Monthly | 19.56% |
| 24% | Monthly | 26.82% |
Interest rates represent the cost of borrowing money, set by the interplay of central bank policy, market forces, and individual credit risk. The Federal Reserve sets the federal funds rate — the rate banks charge each other for overnight lending — which anchors all other rates in the economy. When the Fed raises this rate (to combat inflation), borrowing costs ripple outward: mortgage rates, auto loan rates, credit card APRs, and savings account yields all adjust upward, typically within weeks. The spread between the federal funds rate and consumer loan rates reflects risk premium and profit margin: credit cards charge 15-25% while the federal funds rate might be 5% because card issuers absorb high default rates (3-4% of balances annually are never repaid). Mortgage rates run 1-2 percentage points above the 10-year Treasury yield because mortgages have lower default risk but tie up capital for decades.
Fixed rates lock in a specific rate for the life of the loan — a 30-year mortgage at 6.5% costs exactly 6.5% every year regardless of market changes. Variable (adjustable) rates start lower but fluctuate with a benchmark index, typically the Secured Overnight Financing Rate (SOFR) plus a margin. A variable-rate loan might start at 5.5% (SOFR 4.5% + 1% margin) but rise to 8.5% if the benchmark increases 3 points. The breakeven analysis: if you expect rates to rise by more than the initial discount, a fixed rate saves money over the loan term. If rates fall or stay flat, the variable rate wins. Most adjustable-rate mortgages (ARMs) include caps — a 5/2/5 cap structure means the rate can increase at most 2 points per adjustment period, 5 points over the life of the loan, with an initial cap of 5 points. Understanding cap structures prevents the worst-case surprise of uncapped variable debt.
The nominal interest rate tells you what percentage of the principal you pay annually in interest. The APR (Annual Percentage Rate) includes fees, points, and other costs spread across the loan term, making it the true cost of borrowing. A mortgage at 6.25% interest with $4,000 in origination fees and $2,000 in discount points has an APR of approximately 6.42%. Two loan offers at 6.25% and 6.50% interest might have APRs of 6.55% and 6.52% respectively — making the higher-rate loan actually cheaper due to lower fees. For credit cards, APR and interest rate are essentially identical because cards have no origination fees baked in. The Truth in Lending Act requires lenders to disclose APR, making it the legally mandated comparison metric. However, APR has limitations: it assumes you keep the loan for its full term, so if you refinance or sell after 5 years, a low-rate loan with high upfront fees may cost more than a slightly higher rate with no fees.
Interest rates fundamentally express the time value of money — the principle that a dollar today is worth more than a dollar tomorrow. If you can earn 5% annually, $1,000 today is worth $1,050 in one year, $1,276 in five years, and $1,629 in ten years. Conversely, $1,000 promised ten years from now is worth only $614 in today's dollars at 5% (its present value). This concept underlies every financial decision involving time: whether to pay cash or finance a purchase, whether to take a lump sum or annuity payout, and how to value a stream of future earnings. Inflation adds another layer — a 5% nominal interest rate with 3% inflation yields only 2% real return. If inflation exceeds your interest rate (as happened with savings accounts from 2021-2023 when savings paid 0.5% while inflation hit 8%), you're losing purchasing power despite "earning" interest.
Simple interest charges a fixed percentage of the original principal each period: $10,000 at 5% simple interest earns $500/year, totaling $15,000 after 10 years. Compound interest charges interest on accumulated interest: the same $10,000 at 5% compounded annually reaches $16,289 after 10 years — $1,289 more. Compounding frequency amplifies the effect: 5% compounded monthly yields slightly more than 5% compounded annually because each month's interest starts earning interest sooner. The effective annual rate (EAR) captures compounding: 5% compounded monthly has an EAR of 5.116%. Savings accounts and investments use compound interest (benefiting you), while some personal loans use simple interest (benefiting you, since less interest accrues). Understanding which method applies to your financial products prevents miscalculating returns on savings or costs on loans — a seemingly minor distinction that compounds to significant differences over years and decades.
Interest rates represent the cost of borrowing money, set by the interplay of central bank policy, market forces, and individual credit risk. The Federal Reserve sets the federal funds rate — the rate banks charge each other for overnight lending — which anchors all other rates in the economy. When the Fed raises this rate (to combat inflation), borrowing costs ripple outward: mortgage rates, auto loan rates, credit card APRs, and savings account yields all adjust upward, typically within weeks. The spread between the federal funds rate and consumer loan rates reflects risk premium and profit margin: credit cards charge 15-25% while the federal funds rate might be 5% because card issuers absorb high default rates (3-4% of balances annually are never repaid). Mortgage rates run 1-2 percentage points above the 10-year Treasury yield because mortgages have lower default risk but tie up capital for decades.
Fixed rates lock in a specific rate for the life of the loan — a 30-year mortgage at 6.5% costs exactly 6.5% every year regardless of market changes. Variable (adjustable) rates start lower but fluctuate with a benchmark index, typically the Secured Overnight Financing Rate (SOFR) plus a margin. A variable-rate loan might start at 5.5% (SOFR 4.5% + 1% margin) but rise to 8.5% if the benchmark increases 3 points. The breakeven analysis: if you expect rates to rise by more than the initial discount, a fixed rate saves money over the loan term. If rates fall or stay flat, the variable rate wins. Most adjustable-rate mortgages (ARMs) include caps — a 5/2/5 cap structure means the rate can increase at most 2 points per adjustment period, 5 points over the life of the loan, with an initial cap of 5 points. Understanding cap structures prevents the worst-case surprise of uncapped variable debt.
The nominal interest rate tells you what percentage of the principal you pay annually in interest. The APR (Annual Percentage Rate) includes fees, points, and other costs spread across the loan term, making it the true cost of borrowing. A mortgage at 6.25% interest with $4,000 in origination fees and $2,000 in discount points has an APR of approximately 6.42%. Two loan offers at 6.25% and 6.50% interest might have APRs of 6.55% and 6.52% respectively — making the higher-rate loan actually cheaper due to lower fees. For credit cards, APR and interest rate are essentially identical because cards have no origination fees baked in. The Truth in Lending Act requires lenders to disclose APR, making it the legally mandated comparison metric. However, APR has limitations: it assumes you keep the loan for its full term, so if you refinance or sell after 5 years, a low-rate loan with high upfront fees may cost more than a slightly higher rate with no fees.
Interest rates fundamentally express the time value of money — the principle that a dollar today is worth more than a dollar tomorrow. If you can earn 5% annually, $1,000 today is worth $1,050 in one year, $1,276 in five years, and $1,629 in ten years. Conversely, $1,000 promised ten years from now is worth only $614 in today's dollars at 5% (its present value). This concept underlies every financial decision involving time: whether to pay cash or finance a purchase, whether to take a lump sum or annuity payout, and how to value a stream of future earnings. Inflation adds another layer — a 5% nominal interest rate with 3% inflation yields only 2% real return. If inflation exceeds your interest rate (as happened with savings accounts from 2021-2023 when savings paid 0.5% while inflation hit 8%), you're losing purchasing power despite "earning" interest.
Simple interest charges a fixed percentage of the original principal each period: $10,000 at 5% simple interest earns $500/year, totaling $15,000 after 10 years. Compound interest charges interest on accumulated interest: the same $10,000 at 5% compounded annually reaches $16,289 after 10 years — $1,289 more. Compounding frequency amplifies the effect: 5% compounded monthly yields slightly more than 5% compounded annually because each month's interest starts earning interest sooner. The effective annual rate (EAR) captures compounding: 5% compounded monthly has an EAR of 5.116%. Savings accounts and investments use compound interest (benefiting you), while some personal loans use simple interest (benefiting you, since less interest accrues). Understanding which method applies to your financial products prevents miscalculating returns on savings or costs on loans — a seemingly minor distinction that compounds to significant differences over years and decades.
Interest rates represent the cost of borrowing money, set by the interplay of central bank policy, market forces, and individual credit risk. The Federal Reserve sets the federal funds rate — the rate banks charge each other for overnight lending — which anchors all other rates in the economy. When the Fed raises this rate (to combat inflation), borrowing costs ripple outward: mortgage rates, auto loan rates, credit card APRs, and savings account yields all adjust upward, typically within weeks. The spread between the federal funds rate and consumer loan rates reflects risk premium and profit margin: credit cards charge 15-25% while the federal funds rate might be 5% because card issuers absorb high default rates (3-4% of balances annually are never repaid). Mortgage rates run 1-2 percentage points above the 10-year Treasury yield because mortgages have lower default risk but tie up capital for decades.
Fixed rates lock in a specific rate for the life of the loan — a 30-year mortgage at 6.5% costs exactly 6.5% every year regardless of market changes. Variable (adjustable) rates start lower but fluctuate with a benchmark index, typically the Secured Overnight Financing Rate (SOFR) plus a margin. A variable-rate loan might start at 5.5% (SOFR 4.5% + 1% margin) but rise to 8.5% if the benchmark increases 3 points. The breakeven analysis: if you expect rates to rise by more than the initial discount, a fixed rate saves money over the loan term. If rates fall or stay flat, the variable rate wins. Most adjustable-rate mortgages (ARMs) include caps — a 5/2/5 cap structure means the rate can increase at most 2 points per adjustment period, 5 points over the life of the loan, with an initial cap of 5 points. Understanding cap structures prevents the worst-case surprise of uncapped variable debt.
The nominal interest rate tells you what percentage of the principal you pay annually in interest. The APR (Annual Percentage Rate) includes fees, points, and other costs spread across the loan term, making it the true cost of borrowing. A mortgage at 6.25% interest with $4,000 in origination fees and $2,000 in discount points has an APR of approximately 6.42%. Two loan offers at 6.25% and 6.50% interest might have APRs of 6.55% and 6.52% respectively — making the higher-rate loan actually cheaper due to lower fees. For credit cards, APR and interest rate are essentially identical because cards have no origination fees baked in. The Truth in Lending Act requires lenders to disclose APR, making it the legally mandated comparison metric. However, APR has limitations: it assumes you keep the loan for its full term, so if you refinance or sell after 5 years, a low-rate loan with high upfront fees may cost more than a slightly higher rate with no fees.
Interest rates fundamentally express the time value of money — the principle that a dollar today is worth more than a dollar tomorrow. If you can earn 5% annually, $1,000 today is worth $1,050 in one year, $1,276 in five years, and $1,629 in ten years. Conversely, $1,000 promised ten years from now is worth only $614 in today's dollars at 5% (its present value). This concept underlies every financial decision involving time: whether to pay cash or finance a purchase, whether to take a lump sum or annuity payout, and how to value a stream of future earnings. Inflation adds another layer — a 5% nominal interest rate with 3% inflation yields only 2% real return. If inflation exceeds your interest rate (as happened with savings accounts from 2021-2023 when savings paid 0.5% while inflation hit 8%), you're losing purchasing power despite "earning" interest.
Simple interest charges a fixed percentage of the original principal each period: $10,000 at 5% simple interest earns $500/year, totaling $15,000 after 10 years. Compound interest charges interest on accumulated interest: the same $10,000 at 5% compounded annually reaches $16,289 after 10 years — $1,289 more. Compounding frequency amplifies the effect: 5% compounded monthly yields slightly more than 5% compounded annually because each month's interest starts earning interest sooner. The effective annual rate (EAR) captures compounding: 5% compounded monthly has an EAR of 5.116%. Savings accounts and investments use compound interest (benefiting you), while some personal loans use simple interest (benefiting you, since less interest accrues). Understanding which method applies to your financial products prevents miscalculating returns on savings or costs on loans — a seemingly minor distinction that compounds to significant differences over years and decades.
Interest rates represent the cost of borrowing money, set by the interplay of central bank policy, market forces, and individual credit risk. The Federal Reserve sets the federal funds rate — the rate banks charge each other for overnight lending — which anchors all other rates in the economy. When the Fed raises this rate (to combat inflation), borrowing costs ripple outward: mortgage rates, auto loan rates, credit card APRs, and savings account yields all adjust upward, typically within weeks. The spread between the federal funds rate and consumer loan rates reflects risk premium and profit margin: credit cards charge 15-25% while the federal funds rate might be 5% because card issuers absorb high default rates (3-4% of balances annually are never repaid). Mortgage rates run 1-2 percentage points above the 10-year Treasury yield because mortgages have lower default risk but tie up capital for decades.
Fixed rates lock in a specific rate for the life of the loan — a 30-year mortgage at 6.5% costs exactly 6.5% every year regardless of market changes. Variable (adjustable) rates start lower but fluctuate with a benchmark index, typically the Secured Overnight Financing Rate (SOFR) plus a margin. A variable-rate loan might start at 5.5% (SOFR 4.5% + 1% margin) but rise to 8.5% if the benchmark increases 3 points. The breakeven analysis: if you expect rates to rise by more than the initial discount, a fixed rate saves money over the loan term. If rates fall or stay flat, the variable rate wins. Most adjustable-rate mortgages (ARMs) include caps — a 5/2/5 cap structure means the rate can increase at most 2 points per adjustment period, 5 points over the life of the loan, with an initial cap of 5 points. Understanding cap structures prevents the worst-case surprise of uncapped variable debt.
The nominal interest rate tells you what percentage of the principal you pay annually in interest. The APR (Annual Percentage Rate) includes fees, points, and other costs spread across the loan term, making it the true cost of borrowing. A mortgage at 6.25% interest with $4,000 in origination fees and $2,000 in discount points has an APR of approximately 6.42%. Two loan offers at 6.25% and 6.50% interest might have APRs of 6.55% and 6.52% respectively — making the higher-rate loan actually cheaper due to lower fees. For credit cards, APR and interest rate are essentially identical because cards have no origination fees baked in. The Truth in Lending Act requires lenders to disclose APR, making it the legally mandated comparison metric. However, APR has limitations: it assumes you keep the loan for its full term, so if you refinance or sell after 5 years, a low-rate loan with high upfront fees may cost more than a slightly higher rate with no fees.
Interest rates fundamentally express the time value of money — the principle that a dollar today is worth more than a dollar tomorrow. If you can earn 5% annually, $1,000 today is worth $1,050 in one year, $1,276 in five years, and $1,629 in ten years. Conversely, $1,000 promised ten years from now is worth only $614 in today's dollars at 5% (its present value). This concept underlies every financial decision involving time: whether to pay cash or finance a purchase, whether to take a lump sum or annuity payout, and how to value a stream of future earnings. Inflation adds another layer — a 5% nominal interest rate with 3% inflation yields only 2% real return. If inflation exceeds your interest rate (as happened with savings accounts from 2021-2023 when savings paid 0.5% while inflation hit 8%), you're losing purchasing power despite "earning" interest.
Simple interest charges a fixed percentage of the original principal each period: $10,000 at 5% simple interest earns $500/year, totaling $15,000 after 10 years. Compound interest charges interest on accumulated interest: the same $10,000 at 5% compounded annually reaches $16,289 after 10 years — $1,289 more. Compounding frequency amplifies the effect: 5% compounded monthly yields slightly more than 5% compounded annually because each month's interest starts earning interest sooner. The effective annual rate (EAR) captures compounding: 5% compounded monthly has an EAR of 5.116%. Savings accounts and investments use compound interest (benefiting you), while some personal loans use simple interest (benefiting you, since less interest accrues). Understanding which method applies to your financial products prevents miscalculating returns on savings or costs on loans — a seemingly minor distinction that compounds to significant differences over years and decades.
Interest rates represent the cost of borrowing money, set by the interplay of central bank policy, market forces, and individual credit risk. The Federal Reserve sets the federal funds rate — the rate banks charge each other for overnight lending — which anchors all other rates in the economy. When the Fed raises this rate (to combat inflation), borrowing costs ripple outward: mortgage rates, auto loan rates, credit card APRs, and savings account yields all adjust upward, typically within weeks. The spread between the federal funds rate and consumer loan rates reflects risk premium and profit margin: credit cards charge 15-25% while the federal funds rate might be 5% because card issuers absorb high default rates (3-4% of balances annually are never repaid). Mortgage rates run 1-2 percentage points above the 10-year Treasury yield because mortgages have lower default risk but tie up capital for decades.
Fixed rates lock in a specific rate for the life of the loan — a 30-year mortgage at 6.5% costs exactly 6.5% every year regardless of market changes. Variable (adjustable) rates start lower but fluctuate with a benchmark index, typically the Secured Overnight Financing Rate (SOFR) plus a margin. A variable-rate loan might start at 5.5% (SOFR 4.5% + 1% margin) but rise to 8.5% if the benchmark increases 3 points. The breakeven analysis: if you expect rates to rise by more than the initial discount, a fixed rate saves money over the loan term. If rates fall or stay flat, the variable rate wins. Most adjustable-rate mortgages (ARMs) include caps — a 5/2/5 cap structure means the rate can increase at most 2 points per adjustment period, 5 points over the life of the loan, with an initial cap of 5 points. Understanding cap structures prevents the worst-case surprise of uncapped variable debt.
The nominal interest rate tells you what percentage of the principal you pay annually in interest. The APR (Annual Percentage Rate) includes fees, points, and other costs spread across the loan term, making it the true cost of borrowing. A mortgage at 6.25% interest with $4,000 in origination fees and $2,000 in discount points has an APR of approximately 6.42%. Two loan offers at 6.25% and 6.50% interest might have APRs of 6.55% and 6.52% respectively — making the higher-rate loan actually cheaper due to lower fees. For credit cards, APR and interest rate are essentially identical because cards have no origination fees baked in. The Truth in Lending Act requires lenders to disclose APR, making it the legally mandated comparison metric. However, APR has limitations: it assumes you keep the loan for its full term, so if you refinance or sell after 5 years, a low-rate loan with high upfront fees may cost more than a slightly higher rate with no fees.
Interest rates fundamentally express the time value of money — the principle that a dollar today is worth more than a dollar tomorrow. If you can earn 5% annually, $1,000 today is worth $1,050 in one year, $1,276 in five years, and $1,629 in ten years. Conversely, $1,000 promised ten years from now is worth only $614 in today's dollars at 5% (its present value). This concept underlies every financial decision involving time: whether to pay cash or finance a purchase, whether to take a lump sum or annuity payout, and how to value a stream of future earnings. Inflation adds another layer — a 5% nominal interest rate with 3% inflation yields only 2% real return. If inflation exceeds your interest rate (as happened with savings accounts from 2021-2023 when savings paid 0.5% while inflation hit 8%), you're losing purchasing power despite "earning" interest.
Simple interest charges a fixed percentage of the original principal each period: $10,000 at 5% simple interest earns $500/year, totaling $15,000 after 10 years. Compound interest charges interest on accumulated interest: the same $10,000 at 5% compounded annually reaches $16,289 after 10 years — $1,289 more. Compounding frequency amplifies the effect: 5% compounded monthly yields slightly more than 5% compounded annually because each month's interest starts earning interest sooner. The effective annual rate (EAR) captures compounding: 5% compounded monthly has an EAR of 5.116%. Savings accounts and investments use compound interest (benefiting you), while some personal loans use simple interest (benefiting you, since less interest accrues). Understanding which method applies to your financial products prevents miscalculating returns on savings or costs on loans — a seemingly minor distinction that compounds to significant differences over years and decades.
→ Always compare APY to APY. Never mix APR and APY comparisons.
→ On loans, APR looks lower. The true cost is always higher after compounding.
→ Credit score matters. A 50-point score improvement can save 0.5–1% on rates.
→ Shop multiple lenders. Rate differences compound over years.
See also: Mortgage Payment · Compound Interest · Loan · CD