Loan Payment Calculator
Enter your loan amount, interest rate, and term to see your exact payment, total interest paid, and full amortization breakdown. Switch payment frequency between monthly, bi-weekly, and weekly, add an extra payment to see how much interest you save and how many months you shave off, or reverse-solve to find the loan amount that fits a payment you can afford. Your results update as you type.
Formula
Worked example
A $25,000 loan at 6.5% APR for 5 years (monthly payments): periodic rate = 6.5% / 12 = 0.541667% per month, n = 60 payments. PMT = 25000 x 0.005417 x (1.005417)^60 / ((1.005417)^60 - 1) = 25000 x 0.005417 x 1.3830 / 0.3830 = $489.15 per month. Total paid = $29,349, total interest = $4,349.
How this loan payment calculator works
Enter the loan amount, the annual interest rate (APR), the repayment term in years, and how often you plan to make payments. The calculator solves the standard amortization formula and instantly shows your periodic payment, total interest, and total cost. Switch to "Loan amount from payment" mode to reverse the formula: type in the payment you can afford and the calculator tells you the maximum you can borrow. The amortization schedule below the results shows a year-by-year breakdown of how each payment splits between interest and principal.
Payment frequency: monthly vs. bi-weekly vs. weekly
Most lenders accept monthly payments, but bi-weekly (every two weeks, 26 payments per year) or weekly schedules can save real money. Because you make the equivalent of one extra monthly payment per year on a bi-weekly plan, the loan balance drops faster and less interest accrues. On a $250,000 mortgage at 7% over 30 years, switching from monthly to bi-weekly payments saves around $45,000 in interest and shaves about 4 years off the term. Weekly schedules have a similar but slightly larger effect. Check whether your lender accepts payments more often than monthly before switching.
How extra payments reduce your total interest
Any amount applied beyond the required payment goes straight to principal, which shrinks the balance on which future interest is calculated. On long loans this compounds dramatically: an extra $100 per month on a $25,000, 5-year car loan at 7% trims about $720 in interest and pays it off roughly 8 months early. On a 30-year mortgage the effect is far larger. Use the extra-payment field to test amounts and see the projected savings in the insight panel and the side-by-side balance chart.
Understanding the amortization schedule
Every fixed-rate loan follows the same pattern: in early periods almost all of your payment goes to interest, and only a small slice reduces the principal. As the balance falls, the interest portion shrinks and the principal portion grows, until the final payment is almost entirely principal. This front-loading of interest is why paying off or refinancing a loan early saves disproportionately more than paying it off late. The yearly summary table below shows this shift year by year for your specific numbers.
Typical loan interest rate ranges (2024)
| Loan type | Typical APR range | Common term |
|---|---|---|
| 30-year mortgage | 6% - 8% | 30 years |
| 15-year mortgage | 5.5% - 7% | 15 years |
| Auto loan (new car) | 5% - 9% | 36-72 months |
| Auto loan (used car) | 7% - 14% | 24-60 months |
| Personal loan | 8% - 24% | 1-7 years |
| Student loan (federal) | 5% - 8% | 10-25 years |
| Credit card (carried balance) | 18% - 30%+ | Revolving |
Rates vary by lender, credit score, and market conditions. Check current rates before applying.
Frequently asked questions
What is the standard loan payment formula?
The periodic payment (PMT) for a fixed-rate amortizing loan is: PMT = P x r x (1+r)^n / ((1+r)^n - 1), where P is the principal (loan amount), r is the periodic interest rate (annual rate divided by the number of payments per year), and n is the total number of payments. For a $20,000 loan at 8% APR paid monthly over 4 years: r = 8% / 12 = 0.6667% per month, n = 48 payments, PMT = $488.26 per month.
Does the interest rate in the calculator refer to APR?
Yes, enter the Annual Percentage Rate (APR). The calculator divides this by the number of payments per year to get the periodic rate. If your lender quotes a monthly rate instead, multiply it by 12 before entering it here. Note that APR and APY (annual percentage yield) are different: APY accounts for compounding within the year, while APR does not. Most loan disclosures use APR.
How is bi-weekly payment different from paying half my monthly payment every two weeks?
They produce the same payment size per period, but the schedule differs. A strict bi-weekly plan runs on every-two-week calendar dates, resulting in 26 half-payments (= 13 full monthly equivalents) per year instead of 12. That extra "bonus" payment reduces the principal faster, cutting interest and term. Some lenders charge a fee to set up bi-weekly billing, so verify the math before signing up.
Can I use this for a mortgage, car loan, or personal loan?
Yes. The amortization formula is identical for any fixed-rate installment loan. Enter the loan amount, rate, and term relevant to your loan type. For a mortgage you may want to add property tax and insurance estimates separately, as they appear in your monthly bill (escrow) but are not part of the loan payment formula itself.
What if my interest rate is 0%?
At 0%, no interest accrues and each payment simply divides the principal equally across all periods. Some promotional offers (e.g., 0% auto financing or deferred-interest credit deals) work this way. Enter 0 in the rate field and the calculator handles it correctly without dividing by zero.
How do I find the maximum loan I can afford?
Switch the "Calculate" dropdown to "Loan amount from payment". Enter the payment you can comfortably afford each period, your expected rate, and the term, and the calculator solves for the largest principal that keeps your payment at or below that amount. This is useful for setting a budget before house or car shopping.
Why does most of my early payment go to interest?
Because interest is charged on the outstanding balance. At the start, the balance is at its highest, so the interest portion of each payment is largest. As you pay down the principal, the balance drops and so does the monthly interest charge, leaving more of each payment to reduce the loan. This "front-loading" is why refinancing or paying off a loan in its early years saves proportionally more interest than doing so toward the end.