Extra payments, quantified
Type any additional amount and the calculator instantly re-runs the whole schedule, showing the interest saved and how many months earlier the loan clears.
Free amortization tool
Loan CalculatorMonthly payment, total interest and full amortization schedule
Work out the monthly payment on a personal, student, business or auto loan, see exactly how much interest you will pay, and watch how a small extra payment moves your payoff date years earlier. Weekly and bi-weekly schedules, six currencies and a complete year-by-year breakdown are built in.
- Extra payment modelling
- Full amortization schedule
- Weekly, bi-weekly & monthly
- No sign-up, nothing stored
Loan payment calculator
Loan details
$
%
Pay it off faster (optional)
$
$
Add an extra payment to see how much interest and time you save.
Results update as you type.
Monthly payment
$525.31per month
Principal $25,000Interest $6,519
$31,519Total paid
$6,519Total interest
26.1%Interest vs principal
—Payoff date
Amortization schedule
| Year | Principal | Interest | Balance |
|---|
Figures assume a fixed rate and on-time payments. Lenders may round the final payment.
Why this loan payment calculator is more useful
Most loan calculators stop at the monthly payment. The payment is the least interesting number — what costs you money is the interest, and what saves it is the extra payment nobody shows you.
Real amortization schedule
See principal, interest and remaining balance for every year — or every single payment — in a scrollable table, not a locked preview behind a sign-up.
Weekly and bi-weekly options
Bi-weekly repayment quietly adds one extra monthly payment a year. Switch frequency and the payoff date and interest total update to match.
An actual payoff date
Set your first payment date and get the calendar month the loan ends, so you can plan around it instead of counting periods in your head.
Fees rolled in
Origination and arrangement fees financed into the balance change the true cost. Add them and the interest figure reflects what you will actually repay.
Private and instant
Everything runs in your browser. No email, no credit pull, no lead form — and no numbers leaving your device.
How to calculate a loan payment
Four inputs decide everything: how much you borrow, the rate, the term and how often you pay.
Enter the amount you will actually borrow
Use the financed amount after any deposit or trade-in, and add origination fees separately if the lender rolls them into the balance.
Use the APR, not the headline rate
APR includes compulsory charges, so it is the number that lets you compare two offers fairly. Advertised “rates from” are usually reserved for the strongest credit profiles.
Test two or three terms
A longer term lowers the payment and raises total interest. Run 3, 5 and 7 years and compare the total interest line, not just the monthly figure.
Add an extra payment and watch it move
Even a small round-up hits principal directly. Increase the extra payment until the payoff date and interest saved look worth the squeeze on your budget.
The loan payment formula
Every amortizing loan — personal, auto, student or mortgage — uses the same equation.
| Term | Formula or meaning |
|---|---|
| Payment (amortizing loan) | P × r / (1 − (1 + r)^−n) |
| P | Principal — the amount borrowed, including any financed fees |
| r | Periodic rate — annual rate ÷ 100 ÷ payments per year |
| n | Total number of payments — years × payments per year |
| Interest in one period | remaining balance × r |
| Principal in one period | payment − interest |
| Total interest | (payment × n) − P for a loan with no extra payments |
Worked example: borrow 25,000 at 9.5% APR over 5 years. The periodic rate is 0.095 ÷ 12 = 0.0079167 and n = 60, giving a payment of about 525.31, roughly 6,519 of it interest.
What running the numbers first actually saves you
A loan is a price you pay in months. Seeing the whole schedule before you sign changes which offer you take.
Compare offers properly
Two lenders can quote the same monthly payment on very different terms. Total interest is the only fair comparison, and it is one line away.
Choose the right term
Stretching a loan from 3 to 7 years can cut the payment by a third and more than double the interest. See both numbers before deciding.
Budget with confidence
Know the exact commitment before it hits your account, and check it against your income with our 50/30/20 budget calculator.
Plan an early payoff
Model the round-up you can sustain, then use the debt payoff calculator to order several balances by snowball or avalanche.
Price a car or a home separately
Vehicle and property lending have their own quirks — try the car loan calculator or the mortgage calculator for taxes, PMI and trade-ins.
Judge refinancing honestly
Enter the balance and the new rate, then compare remaining interest against your current deal plus any fees to see if switching is worth it.
Loan calculator FAQs
The questions borrowers ask most before signing.
How is a monthly loan payment calculated?
The standard amortizing formula is payment = P × r ÷ (1 − (1 + r)−n), where P is the amount borrowed, r is the annual rate divided by 12, and n is the number of monthly payments. Each payment covers the interest accrued that month first, and whatever is left reduces the balance.
Why does so little of my early payment go to principal?
Interest is charged on the balance you still owe, and that balance is at its highest at the start. As the balance falls, the interest portion shrinks and the principal portion grows. The schedule in this calculator shows the crossover point for your loan.
How much does an extra payment really save?
Extra money goes straight to principal, so it removes all the future interest that balance would have generated. On a 25,000 loan at 9.5% over 5 years, an extra 50 a period typically saves over 900 in interest and clears the loan several months early. Enter your own figures to see the exact saving.
Is bi-weekly repayment better than monthly?
Usually, yes. Twenty-six bi-weekly payments equal thirteen monthly payments a year rather than twelve, so you make one extra payment annually without noticing much. Confirm your lender applies each payment immediately rather than holding it until month end.
What is the difference between interest rate and APR?
The interest rate is the cost of borrowing the money. The APR also includes compulsory fees such as origination charges, so it is a more complete measure of cost and the fairer number for comparing two offers. Use the APR in this calculator where you have it.
Does this calculator work for personal, auto, student and business loans?
Yes. Any fixed-rate amortizing loan uses the same maths, so the results apply to personal loans, car finance, student loans, equipment finance and mortgages alike. Variable-rate or interest-only products will differ once the rate or structure changes.
Should I include fees in the loan amount?
Include them if the lender adds them to the balance rather than taking them from the amount you receive. Use the fees field to keep them visible — financed fees accrue interest for the whole term, which is why a low rate with a large fee can cost more than a slightly higher rate with none.
Are these results a loan offer?
No. This is an educational estimate based on the figures you enter and assumes a fixed rate with on-time payments. Your lender may round the final payment, charge late or early-repayment fees, or price the loan differently after a credit check. Always confirm the numbers in your loan agreement.
See the whole cost before you sign
Change the term, switch to bi-weekly, add a small extra payment — then look at the total interest line. That one number is the difference between a good loan and an expensive one.