Loan calculator with amortisation schedule
Work out the monthly payment, total interest and true cost of any amortising loan, with a full payment schedule you can download as CSV.
- Runs in your browser
- Nothing you enter is sent
- Free, no account
Total interest
$6,502.75
Total repaid
$31,502.75
principal + interest
Cost of borrowing
$6,502.75
interest + fees
Interest as % of loan
26%
effective annual rate 9.92%
Final payment
January 1, 2031
5 years
First payment interest
$197.92
of a $525.05 payment
- Principal79.4%$25,000.00
- Interest20.6%$6,502.75
What you hand over in total, split between the money you borrowed and the price of borrowing it.
- Scheduled balance
Formula and working
Monthly payment
M = P × i / (1 − (1 + i)^−n) i = 9.5% ÷ 12 = 0.00791667 n = 60 M = 25,000 × 0.00791667 ÷ (1 − 1.00791667^−60) = $525.05
Total repaid
Total = M × n (adjusted for the rounded final payment) Total = 525.05 × 60 = $31,502.75
Total interest
Interest = Total − P Interest = 31,502.75 − 25,000 = $6,502.75
Effective annual rate
EAR = (1 + i)^12 − 1 EAR = (1 + 0.00791667)^12 − 1 = 9.925%
Each month, interest is charged on the outstanding balance only; the rest of the payment reduces the principal, which is why the interest share falls over time.
| # | Date | Payment | Principal | Interest | Balance |
|---|---|---|---|---|---|
| 1 | Feb 2026 | $525.05 | $327.13 | $197.92 | $24,672.87 |
| 2 | Mar 2026 | $525.05 | $329.72 | $195.33 | $24,343.15 |
| 3 | Apr 2026 | $525.05 | $332.33 | $192.72 | $24,010.82 |
| 4 | May 2026 | $525.05 | $334.96 | $190.09 | $23,675.86 |
| 5 | Jun 2026 | $525.05 | $337.62 | $187.43 | $23,338.24 |
| 6 | Jul 2026 | $525.05 | $340.29 | $184.76 | $22,997.95 |
| 7 | Aug 2026 | $525.05 | $342.98 | $182.07 | $22,654.97 |
| 8 | Sep 2026 | $525.05 | $345.70 | $179.35 | $22,309.27 |
| 9 | Oct 2026 | $525.05 | $348.43 | $176.62 | $21,960.84 |
| 10 | Nov 2026 | $525.05 | $351.19 | $173.86 | $21,609.65 |
| 11 | Dec 2026 | $525.05 | $353.97 | $171.08 | $21,255.68 |
| 12 | Jan 2027 | $525.05 | $356.78 | $168.27 | $20,898.90 |
Showing 1–12 of 60 rows
Assumptions
- A fixed rate for the whole term with interest compounded monthly and equal monthly payments.
- Interest accrues on the outstanding balance at the start of each month; the payment is applied at the end of it.
- Fees are treated as paid up front rather than added to the balance, so they do not accrue interest.
- Late fees, payment holidays, insurance products and variable-rate resets are not modelled.
How to use the loan calculator
- Enter the loan amount — the sum actually advanced to you, not the total you will repay.
- Enter the annual interest rate. If your offer quotes an APR that includes fees, put the interest rate here and the fee in the fee field, so the two are separated.
- Set the term in years, with extra months if your offer is something like 42 or 54 months.
- Optionally add an extra monthly principal payment to see the interest saved and the months removed.
- Read the payment, the total interest and the cost of borrowing, then export the full schedule as CSV.
What the calculator is modelling
This is a standard amortising loan: a fixed rate, equal monthly payments, and a balance that reaches zero on the final payment. That structure covers personal loans, most student loans, home improvement loans, business term loans and the vast majority of car finance.
Each month the lender charges interest on the balance outstanding at the start of the month. Whatever is left of your payment reduces the principal. Because the balance falls a little every month, the interest charge falls too, and the principal portion of a fixed payment grows. That is the whole of amortisation, and the schedule below the calculator shows it line by line.
Monthly payment per 10,000 borrowed
Multiply by your loan amount in units of ten thousand. A 25,000 loan at 10% over five years is 2.5 × 212.47 = 531.18 a month.
| Rate | 1 year | 2 years | 3 years | 5 years | 7 years |
|---|---|---|---|---|---|
| 4% | 851.50 | 434.25 | 295.24 | 184.17 | 136.69 |
| 6% | 860.66 | 443.21 | 304.22 | 193.33 | 146.09 |
| 8% | 869.88 | 452.27 | 313.36 | 202.76 | 155.86 |
| 10% | 879.16 | 461.45 | 322.67 | 212.47 | 166.01 |
| 12% | 888.49 | 470.73 | 332.14 | 222.44 | 176.53 |
| 15% | 902.58 | 484.87 | 346.65 | 237.90 | 192.97 |
| 18% | 916.80 | 499.24 | 361.52 | 253.93 | 210.18 |
| 20% | 926.35 | 508.96 | 371.64 | 264.94 | 222.06 |
Total interest per 10,000 borrowed
The same loans, shown as the total interest paid rather than the monthly payment. This is the number that shows why a longer term is expensive even when the payment looks comfortable.
| Rate | 1 year | 2 years | 3 years | 5 years | 7 years |
|---|---|---|---|---|---|
| 4% | 218 | 422 | 629 | 1,050 | 1,482 |
| 8% | 439 | 855 | 1,281 | 2,166 | 3,092 |
| 12% | 662 | 1,298 | 1,957 | 3,347 | 4,828 |
| 15% | 831 | 1,637 | 2,480 | 4,274 | 6,209 |
| 20% | 1,116 | 2,215 | 3,379 | 5,896 | 8,653 |
At 20%, stretching a 10,000 loan from three years to seven more than doubles the interest, from 3,379 to 8,653, while only cutting the payment by about 40%. The shortest term you can comfortably afford is almost always the cheapest choice.
Interest rate, APR and the cost of borrowing
The interest rate prices the money. The APR also folds in compulsory fees and is expressed as an annual rate, which makes it the better comparison number between two offers with different fee structures. The total cost of borrowing — interest plus fees in currency, not percent — is the figure that tells you what the loan really costs, and it is what this calculator puts next to the payment.
One thing to check on any quote: whether interest is charged on the reducing balance, as modelled here, or as a flat rate on the original amount for the whole term. Flat-rate quotes look cheap and are typically close to double the equivalent reducing-balance rate.
Accuracy
All arithmetic is done with arbitrary-precision decimals and rounded to the minor currency unit exactly once per payment, which is how servicers do it. The final instalment absorbs the rounding residue, so the balance lands on zero. Expect a match to the penny against a standard fixed-rate statement, and small differences against lenders who use daily interest accrual, actual-day counts or a different rounding convention.
Questions
What kind of loans does this cover?
Any loan repaid in equal monthly instalments at a fixed rate: personal loans, student loans, business loans, home improvement loans and most car finance. Interest-only and balloon structures are not covered.
What is the difference between the interest rate and the APR?
The interest rate prices the borrowing itself. APR also folds in fees, so it is higher whenever there is an arrangement fee. Enter your fee separately and the tool shows the total cost of borrowing, which is the figure worth comparing between lenders.
Why is so much of my first payment interest?
Interest is charged on the outstanding balance, which is at its largest at the start. As the balance falls, the interest portion of a fixed payment shrinks and the principal portion grows — the schedule shows the exact crossover.
Does paying extra each month help?
Yes, and the effect is bigger than most people expect. Extra money goes straight against the principal, so it removes all the future interest that balance would have generated. Add an amount in the extra field to see the interest saved and time cut.