Loan calculator: monthly payment, total interest and amortization
Enter the amount, the annual rate and the term to see the monthly payment, the total interest and how each payment splits between interest and principal.
Standard amortization formula; APR and Canadian compounding notes from the CFPB and FCACLast reviewed: October 9, 2026
Amortization schedule
InterestPrincipalThe payment is the same every month, but the interest part starts large and shrinks while the principal part grows. Amounts in dollars.
| Period | Payment | Interest | Principal | Balance after | Split of payment |
|---|---|---|---|---|---|
| Totals for the full term | 0.00 |
The short answer
Monthly payment = amount × i ÷ (1 − (1 + i)^−n), where i is the annual rate ÷ 12 and n is the number of months. A $25,000 loan at 7% for 60 months costs $495.03 a month and $4,701.80 in total interest. Early payments are mostly interest.
How it is calculated
Payment = P × i ÷ (1 − (1 + i)−n)
P = amount borrowed, i = monthly rate (annual rate ÷ 12), n = number of monthly payments.
Each month, interest = balance × i, and the rest of the payment reduces the balance.
With semi-annual compounding, i = (1 + annual rate ÷ 2)1/6 − 1.
Worked example
Maria finances a used car: $25,000 at 7% APR for 5 years (60 monthly payments).
- Monthly rate: 7% ÷ 12 = 0.5833%
- Payment: 25,000 × i ÷ (1 − (1 + i)−60) = $495.03
- Month 1: $145.83 interest and $349.20 principal; balance $24,650.80
- Total of 60 payments: $29,701.80, of which $4,701.80 is interest
- Same loan over 6 years: $426.23 a month, but $5,688.21 in interest
Maria pays $495.03 a month and $4,701.80 in interest over 5 years.
Quick reference table
| APR | 36 months | 48 months | 60 months | 72 months |
|---|---|---|---|---|
| 4% | $295.24 | $225.79 | $184.17 | $156.45 |
| 6% | $304.22 | $234.85 | $193.33 | $165.73 |
| 8% | $313.36 | $244.13 | $202.76 | $175.33 |
| 10% | $322.67 | $253.63 | $212.47 | $185.26 |
| 12% | $332.14 | $263.34 | $222.44 | $195.50 |
Special cases and common mistakes
- A longer term lowers the payment but raises the cost. In the example, stretching 60 months to 72 cuts the payment by $68.80 but adds $986.41 of interest.
- Interest rate vs APR. The CFPB describes the APR as a broader measure of the cost of borrowing than the interest rate, including points, broker fees and other charges. Enter the interest rate to match your payment; use the APR to compare offers.
- Canadian fixed-rate mortgages. In the FCAC sample fixed-rate mortgage agreement the interest is "compounded twice per year but charged monthly". Choose semi-annual compounding for that case. FCAC says the information box must show how interest is compounded, so check yours.
- The schedule shows where the money goes. The first year is listed month by month and later years are grouped by year, so you can see the balance fall faster as interest shrinks.
Frequently asked questions
How do I calculate a monthly loan payment?
Divide the annual rate by 12 to get the monthly rate i, then payment = amount × i ÷ (1 − (1 + i)^−n), where n is the number of months. The calculator does this and builds the full amortization schedule.
What is the payment on a $30,000 car loan for 60 months?
At 6% APR it is $579.98 a month with $4,799.04 total interest. At 9% it is $622.75 a month.
How much is the payment on a $300,000 mortgage?
At 6% over 30 years, principal and interest come to $1,798.65 a month, and total interest is $347,514.57. Property taxes and insurance are extra.
Why is most of my early payment interest?
Interest is charged on the balance you still owe. The balance is largest at the start, so early payments are mostly interest, and the principal share grows each month.
Should I enter the APR or the interest rate?
For the exact payment, the interest rate. The APR includes fees and is usually a little higher, so it gives a slightly higher payment. The APR is the better number for comparing loan offers.
How are Canadian mortgage payments different?
A Canadian mortgage information box must state how interest is compounded, and the FCAC sample fixed-rate agreement compounds twice a year but charges monthly. Semi-annual compounding gives a slightly lower payment than monthly compounding at the same rate. If your agreement says so, pick semi-annual in the calculator.
Sources
- CFPB: What is the difference between a mortgage interest rate and an APR? (Last reviewed: October 9, 2026)
- FCAC: Credit agreement for a fixed interest loan for a fixed amount (mortgage), sample information box (Last reviewed: October 9, 2026)
- FCAC: Getting a mortgage, know your rights (information box contents) (Last reviewed: October 9, 2026)