Debt management

Loan Interest Calculator

Enter your loan amount, rate and term to see the monthly payment and the total interest over the loan.

  • Free
  • No sign-up
  • Updated for 2026

Loan details

$
%
yr
Extra payments
$

per month

Enter the loan amount, rate and term to see the interest.

Worked example

With these example inputs:

  • Loan amount$10,000
  • Interest rate9%
  • Loan term4 yr

Monthly payment: $249

  • Loan amount$10,000
  • Total interest$1,945
  • Total of payments$11,945
  • Payoff time4 yr

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What this loan interest calculator does

This calculator finds your monthly loan payment. You enter the loan amount, rate, and term. The tool shows the payment in the currency you choose. It also reveals the total interest you pay. This is a handy borrowing tool. You can test different figures. The result helps you weigh a loan.

What loan interest is

Loan interest is the cost of borrowing money. The lender charges it on your balance. The rate sets how much it costs. It is built into each payment. So you repay more than you borrowed. The gap is the total interest. You see it in your chosen currency.

How it is calculated

The tool takes your loan amount. It spreads it over the term in equal payments. It adds interest at your rate each month. The payment is set so the loan ends at zero. The total interest is the extra you pay. The calculator runs the numbers for you.

What the result tells you

The result shows your monthly payment. A loan of ten thousand at nine percent over four years costs about two hundred fifty a month. A higher rate or amount raises it. A longer term lowers each payment. So it shows what you must pay. It is a clear monthly figure.

Principal and interest

Each payment splits into principal and interest. Principal pays down what you borrowed. Interest is the cost of the loan. Early payments are mostly interest. Later ones are mostly principal. So the split shifts over time. This is how a loan amortizes.

The total interest

The total interest is the full cost of the loan. It is everything you pay above the amount. A higher rate or longer term raises it. So a small loan can still cost a lot. The tool shows this figure clearly. So you see the true price. Watch it before you borrow.

Making extra payments

An extra payment goes straight to principal. So it shrinks the balance faster. That cuts the interest you pay. It can also end the loan early. Even a small extra helps over time. So pay more when you can. It is a simple way to save.

How to use it

Enter the loan amount first. Add the rate and term. Read your monthly payment in your currency. Add an extra payment to see the effect. Then adjust the inputs and look again. Compare a few rates. Use it to weigh a loan.

The limits of this calculator

It has a few clear limits. It assumes a fixed rate for the term. It does not include any fees. Some loans charge an origination fee. A variable rate can change the payment. So treat it as an estimate. So take the figure as a guide.

Common mistakes to avoid

A common mistake is ignoring the total interest. A low payment can still cost a lot. Another is focusing only on the payment. A longer term lowers it but adds interest. Some forget about fees. Others skip comparing rates. A clear number keeps you from these slips.

A final tip

Use this to weigh a loan. Remember the payment covers principal and interest. Watch the total interest closely. Compare a few rates before you borrow. Pay a little extra when you can. Do not pick a term too long. A second look sharpens your view.

Frequently asked questions

How much interest will I pay?

The total interest is the sum of every payment minus the amount borrowed. A $10,000 loan at 9% over 4 years costs roughly $1,940 in interest.

How can I reduce the interest?

A shorter term, a lower rate or extra payments all cut the total interest. The breakdown shows how much of your payments goes to interest versus principal.