Loan Payment Calculator
The other side of the ledger. See the equal monthly payment, total interest and total cost of any loan — and how much of each payment is principal versus interest over time.
Borrowing $500,000 at 5% for 30 years means a monthly payment of about $2,684, a total cost of roughly $966,280, and about $466,280 in interest. The earlier you pay down principal, the less interest you pay overall. This calculator shows your equal monthly payment, total interest, total cost, and an amortization breakdown year by year. Adjust the loan amount, rate or term below to compare options and see the impact of extra repayments.
Your loan
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Loans are amortized monthly: your rate is applied as an effective monthly rate (annual ÷ 12) — the standard fixed-rate mortgage convention.
Show yearly breakdown
| Year | Remaining balance | Principal paid | Interest paid |
|---|
How this calculation works
The formula
This is the standard equal-installment (amortizing) loan. With loan amount P, monthly rate i and N months, the monthly payment is:
Each month you pay interest on the remaining balance, and the rest reduces principal. Early payments are mostly interest; later payments are mostly principal.
Assumptions
- The interest rate is fixed for the whole term (equal installments, principal + interest).
- Payments are made at the end of each month.
- Loans are amortized monthly — the rate is applied as an effective monthly rate (annual ÷ 12), the standard fixed-rate mortgage convention.
- Fees, taxes, insurance and other charges are not included.
- The result is in nominal dollars — inflation is not modeled.
Educational purposes only. Not financial advice. See the full methodology and disclaimer.
Loans, explained
How is the monthly payment calculated?
M = P·i·(1+i)^N / ((1+i)^N − 1), where P is the loan amount, i the monthly rate and N the number of months. Every month you pay the same amount; interest is charged on the remaining balance and the rest pays down principal.