Loan calculator
Monthly payment, total interest and a full amortization schedule you can export.
Straight off the principal
Over 60 payments
17.4% of what you borrowed
Balance over time. The curve is steepest at the end — early payments are mostly interest.
Amortization by year
| Year | Interest | Principal | Balance |
|---|---|---|---|
| 1 | $1,496.23 | $4,373.62 | $20,626.38 |
| 2 | $1,203.32 | $4,666.53 | $15,959.86 |
| 3 | $890.79 | $4,979.05 | $10,980.81 |
| 4 | $557.34 | $5,312.51 | $5,668.30 |
| 5 | $201.55 | $5,668.30 | $0.00 |
First twelve payments
| # | Payment | Interest | Principal | Balance |
|---|---|---|---|---|
| 1 | $489.15 | $135.42 | $353.74 | $24,646.26 |
| 2 | $489.15 | $133.50 | $355.65 | $24,290.61 |
| 3 | $489.15 | $131.57 | $357.58 | $23,933.03 |
| 4 | $489.15 | $129.64 | $359.52 | $23,573.51 |
| 5 | $489.15 | $127.69 | $361.46 | $23,212.05 |
| 6 | $489.15 | $125.73 | $363.42 | $22,848.63 |
| 7 | $489.15 | $123.76 | $365.39 | $22,483.24 |
| 8 | $489.15 | $121.78 | $367.37 | $22,115.87 |
| 9 | $489.15 | $119.79 | $369.36 | $21,746.51 |
| 10 | $489.15 | $117.79 | $371.36 | $21,375.15 |
| 11 | $489.15 | $115.78 | $373.37 | $21,001.78 |
| 12 | $489.15 | $113.76 | $375.39 | $20,626.38 |
How it works
An amortising loan has a fixed payment, of which a shrinking part is interest and a growing part is principal. The payment is set so that the balance reaches exactly zero on the final period.
P = L · i / (1 − (1 + i)^−n)
L = amount borrowed
i = annual rate ÷ 12
n = number of monthly payments Why the early payments feel useless
Interest is charged on the balance you still owe, and at the start that is nearly all of it. On a $25,000 loan at 6.5%, the first payment puts about $135 toward interest — money that buys you nothing. By the final year almost every dollar reduces the balance. This is why an extra payment made in year one is worth far more than the same payment made in year five.
Extra payments
Anything above the required payment comes straight off the principal, which reduces every future interest charge. The effect compounds: paying an extra $100 a month on a $25,000 5-year loan clears it roughly a year early and saves several hundred in interest. Confirm with your lender that extra payments are applied to principal and that there is no prepayment penalty.
Rate versus APR
The interest rate is what accrues on the balance. The APR also folds in origination fees and points, so it is the number to use when comparing offers. Two loans with the same rate and different fees have different APRs, and the higher one costs more.