Loan Payment Calculator
Calculate your fixed monthly loan payment, total amount paid, and total interest from principal, rate, and term.
- Monthly payment
- $1,199.10
- Total paid
- $431,676.38
- Total interest
- $231,676.38
Principal vs. interest over time
Total paid at year 30: $431,676.38
How it works
This uses the standard fixed-rate amortization formula: M = P·r(1+r)ⁿ / ((1+r)ⁿ − 1), where P is the loan principal, r is the monthly interest rate (annual rate ÷ 12), and n is the total number of monthly payments (years × 12).
The payment M stays the same every month, but the split between interest and principal shifts over time — early payments are mostly interest, later payments are mostly principal, because interest is charged on the remaining balance each month. The chart below re-amortizes the loan payment by payment to show that cumulative split, which is usually the more useful question than the total interest alone.
If the interest rate is 0%, the formula simplifies to just the principal divided evenly across all payments.
FAQ
Why does the total interest seem so high on a 30-year term?
Interest compounds on whatever balance remains, and a 30-year term means a lot of months where a large balance is still outstanding. Shortening the term or making extra principal payments reduces the total interest substantially, since it shrinks the balance interest accrues on sooner.
Does this include taxes, insurance, or other fees?
No — this calculates only the principal-and-interest payment from the loan amount, rate, and term you enter. Real monthly obligations (e.g. a mortgage escrow) often include other costs on top of this.