Loan Payment Calculator

1. Enter the loan amount, interest rate (apr), term entered in and loan term.
2. Optionally add extra payment per month — leave blank to skip.
3. Read the highlighted result first, then the breakdown below it. Load the worked example to check the math by hand.

An amortized loan charges interest on the balance you still owe, so the split between interest and principal shifts every month even though the payment stays the same.

• Monthly rate r = APR ÷ 100 ÷ 12, payments n = term in months
• Payment = principal × r ÷ (1 − (1 + r)^−n); at 0% APR it is principal ÷ n
• Total interest = payment × n − principal
• With an extra payment the balance is amortized month by month: interest = balance × r, principal reduction = payment + extra − interest

The monthly payment repays the whole principal plus interest by the end of the term. Total interest is what the loan costs you on top of the amount borrowed, and the extra-payment figures come from amortizing the balance month by month.

Common mistakes and assumptions

• Entering the term in the wrong unit — check the months/years selector before reading the payment.
• Confusing APR with a fee-inclusive cost. The math treats the rate you enter as the periodic interest rate; origination or closing fees are not included.
• Assuming every lender applies extra payments to principal automatically; many require you to ask.

A $25,000 loan at 9% APR over 5 years, with $150 extra sent each month.

1. 1Monthly rate = 9 ÷ 100 ÷ 12 = 0.0075, n = 60 payments.
2. 2Payment = $25,000 × 0.0075 ÷ (1 − 1.0075^−60) = $518.96.
3. 3Scheduled total interest = $518.96 × 60 − $25,000 = $6,137.53.
4. 4Sending $668.96 instead clears the loan in 46 months and cuts total interest to about $4,687.
5. 5That is roughly $1,450 saved for the same loan, purely from timing.

What is the monthly payment on a $10,000 loan?

At 10% over three years it is $322.67 a month, and the loan costs about $1,616 in interest. Stretch the same loan to five years and the payment falls to $212.47 while interest rises to roughly $2,748 — the payment and the cost move in opposite directions.

Is APR the same as interest rate here?

For this calculation they are treated the same: the rate is applied monthly to the outstanding balance. A true APR also folds in fees, so if your lender quoted an APR that includes origination costs, your payment on the stated principal will be slightly lower than this figure.

Does a longer term make a loan cheaper?

It makes the payment smaller, not the loan cheaper. Every extra month is another month of interest charged on the balance, so the total repaid rises. Pick the shortest term whose payment you can comfortably carry.

Do extra payments always reduce interest?

Yes, as long as your lender applies them to principal and does not charge a prepayment penalty. Confirm both before you start sending more — some servicers hold extra money as a prepaid installment instead.

Why does the last payment differ?

Amortization rarely lands on exactly zero, so the final payment is usually a few dollars smaller. When an extra payment is included, this calculator amortizes month by month and lets the last payment be partial.

Can I see the month-by-month split of principal and interest?

Not here — this page returns the payment and the totals. For the full table of what each payment does to the balance, use the Amortization Calculator, which builds the schedule year by year or month by month.

Can I use this for a mortgage?

For principal and interest, yes. For a home you will also want property tax, insurance, HOA, and PMI, which the mortgage calculator adds.

Worked answers with real figures and stated assumptions, written around the question people usually arrive with.

• How much house can I afford on my salary?Convert income, debts and a down payment into a home-price range, with the tax and insurance drag included.
• How much extra should I pay on my debt each month?See what $50, $100 or $250 extra does to your payoff date and interest, and reverse-solve a target date.
• 15-year vs 30-year mortgage: the real cost comparisonPayment, total interest and equity compared, plus the flexible middle option most buyers overlook.