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Loan Calculator

Estimate your monthly payment, total cost, and total interest on any fixed-rate loan.

Loan Calculator

Standard in the US/EU. The rate is divided across the payment frequency.

Payment

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Fill in the form to see your payment.

What is a loan calculator?

A loan calculator turns three numbers — how much you borrow, the interest rate, and how long you take to repay — into the periodic payment that fully repays the loan. It uses the standard amortization formula, the same one banks and lenders use, so you can compare offers, plan a budget, or decide between a shorter or longer term before signing anything.

How to use it

Four inputs, instant results.

  1. Enter the loan amount (the principal you'll actually borrow, after any down payment).
  2. Enter the annual interest rate (APR works fine for a quick estimate; the result is the periodic payment that fully repays the loan).
  3. Enter the term in years.
  4. Pick the payment frequency — monthly is by far the most common.

The formula

This is the standard fixed-rate amortization formula. Each payment is constant; the split between principal and interest shifts over time (more interest at the start, more principal toward the end).

M = P × [ r(1+r)n ] / [ (1+r)n − 1 ]

  • P — principal (loan amount).
  • r — periodic interest rate (annual rate ÷ payments per year).
  • n — total number of payments (years × payments per year).
  • M — payment per period.

How term affects total interest

Same loan ($200,000 at 7% APR), different terms. Longer terms drop the monthly payment but multiply the interest you pay over the life of the loan.

Term Monthly payment Total interest
10 years$2,322$78,675
15 years$1,798$123,578
20 years$1,551$172,144
30 years$1,331$279,018

Illustrative numbers, principal $200,000 at 7% APR. Run your own scenario above.

Frequently asked questions

Is APR the same as the interest rate?
Not exactly. The interest rate is the cost of borrowing the principal. The APR adds in some fees and is meant to make offers comparable. For a back-of-envelope estimate the two are close enough; for the exact figure, use the rate listed on your contract.
Why does total interest grow so much with a longer term?
Because interest is charged on the outstanding balance every period. A longer term means the balance stays high for longer, so you pay interest on more dollars for more periods. The monthly payment shrinks, but the total cost climbs.
What happens if I make extra payments?
Any extra amount applied to principal reduces the balance early, which shrinks every interest charge that follows it. Even small extra payments can save thousands and shorten the term significantly.
Does this calculator handle prepayment penalties or fees?
No. It assumes a clean fixed-rate loan with no fees, no balloon, no prepayment penalty. Always read the contract for taxes, insurance, origination fees, and other charges that affect the true cost.
Monthly vs bi-weekly: does it really make a difference?
Yes — modestly. With true bi-weekly payments you make 26 half-payments a year, which is the equivalent of 13 monthly payments instead of 12. That extra payment chips away at principal and shortens the term.
Is this suitable for a mortgage?
For the principal-and-interest portion, yes. A real mortgage payment usually also includes property tax, homeowners insurance, and possibly PMI or HOA dues. Use a dedicated mortgage calculator if you need the all-in monthly cost.
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