Money

Loan Payment Calculator

The monthly payment on any fixed-rate loan, the total interest, and where every payment goes.

Enter the amount, rate and term to see the payment and the full schedule.

Loan amount

Interest rate

The nominal annual rate.

Loan term

Payment frequency

Extra with each payment

Optional. Goes straight to principal and shortens the loan.

Exact calculation. Given your inputs, this is the answer — no estimation involved.

How this calculator works

The payment comes from the standard fixed-rate amortisation formula, which finds the level amount that exactly retires the loan over the term. A zero-rate loan simply divides evenly, which is what the formula converges on as the rate approaches zero.

The schedule is generated month by month rather than approximated, and the final payment is trimmed to land the balance exactly on zero — the same thing a servicer does. Without that trim, total interest is overstated by up to one payment.

The rate you enter is the nominal annual rate. On a loan with no fees that is the same as the APR; where fees are financed the APR is higher, and the Personal Loan Calculator handles that case.

The formula

Exactly what happens to your numbers, step by step.

The payment
```
payment = P · i ÷ (1 − (1 + i)⁻ⁿ)
```
P is the principal, i the periodic rate, n the number of payments. For monthly payments, i is the annual rate ÷ 12.

Each period

interest  = balance × i
principal = payment − interest
balance   = balance − principal

Total cost

total interest = total of payments − principal

A worked example

A $25,000 loan at 5% over five years.

What you enter

Loan amount: $25,000
Interest rate: 5.0%
Term: 5 years

The working

Monthly rate: 5% ÷ 12 = 0.4167%
Payments: 60
Payment: $471.78
Total of payments: $28,307
Total interest: $3,307

$471.78 a month · $3,307 of interest

Interest is 13% of what you borrowed. Adding $100 a month would clear the loan about a year early and save roughly $700.

Assumptions

Every result here rests on these. Change your inputs and the result changes with them.

A fixed interest rate for the whole term.
Payments are made on schedule, in equal amounts.
Interest is simple interest on the outstanding balance, compounded at the payment frequency.
No origination fees, insurance or prepayment penalties.

Questions people ask

How is a loan payment calculated?

From the principal, the periodic interest rate and the number of payments, using the annuity formula above. It finds the single level payment that covers the interest each period and retires the principal exactly at the end.

What is the difference between the interest rate and the APR?

The interest rate is what accrues on the balance. The APR also includes fees, expressed as an annual rate. With no fees they are the same; with an origination fee the APR is higher and is the better comparison figure.

Why does a longer term cost so much more?

Because interest accrues on the balance for longer. Doubling the term does not double the interest — it more than doubles it, because the balance stays high for far longer.

Does paying extra help?

Considerably, especially early on. Extra money goes straight to principal, and every dollar of principal retired early cancels all the future interest that dollar would have accrued.

Sources and review

This calculator uses standard arithmetic with no external rules or published rates, so there is nothing to cite beyond the formulas shown above.

Methodology version 1.0.0 · Last reviewed September 6, 2026