What does the Payment Calculator solve for?

Either a fixed monthly payment (given the loan amount, rate and term) or the payoff term in months (given the loan amount, rate and a fixed monthly payment). Switch modes at the top to choose which one you need.

How does the Payment Calculator compute the monthly payment?

It uses the standard amortized-loan formula: M = P × r × (1+r)^n ÷ ((1+r)^n − 1), where r is the monthly interest rate and n is the number of monthly payments. A 0% rate simply spreads the loan evenly across the term.

Why does the Payment Calculator say my payment will never pay off the loan?

If your monthly payment is less than or equal to that month's interest charge on the balance, the balance never shrinks. The Payment Calculator flags this so you can enter a payment above the interest-only amount.

Is the Payment Calculator's result exact?

No — it is an estimate only, not financial advice. Real loans may round payments, add fees, or compound interest slightly differently, so confirm final numbers with your lender.

Does the Payment Calculator upload my loan numbers anywhere?

No. Every calculation happens locally in your browser. The amount, rate, term and payment you enter are not sent to ArrayKit or anywhere else.

Can the Payment Calculator handle a 0% interest loan?

Yes. At 0% interest, the monthly payment is simply the loan amount divided by the term, and the payoff term for 'Find payoff term' is the amount divided by the payment, with no interest added.

Payment Calculator Online

Solve a fixed loan payment or the term it takes to pay one off, right in your browser. Estimates only, and your figures stay on your device.

The Payment Calculator runs entirely in your browser. The loan amount, rate, term and payment you enter never leave your device. Results are estimates only, not financial advice.

Open the Loan Calculator

About Payment Calculator

Payment Calculator solves two related loan questions: what is the fixed monthly payment for a given loan amount, rate and term, or how many months will it take to pay off a loan at a fixed monthly payment you already know. Switch between 'Find payment' and 'Find payoff term' modes, enter the loan amount and annual interest rate, and the calculator applies the standard amortized-loan formula to solve the missing figure along with the total interest you'll pay. It is useful for comparing installment loan offers, checking whether a payment you can afford will actually clear a balance, or sanity-checking a lender's quoted numbers before signing. These are estimates only, not financial advice — confirm final terms with your lender. Every calculation runs locally in your browser; nothing is uploaded.

Features

Solves the fixed monthly payment from loan amount, rate and term
Solves the payoff term (in months) from loan amount, rate and a fixed payment
Uses the standard amortized-loan formula for accurate, lender-style figures
Shows total interest paid over the full term in either mode
Handles a 0% interest rate as an even split of the principal
Clear error when a payment is too low to ever cover the monthly interest
One-click copy of a plain-text summary of all results
Runs entirely in your browser — your loan figures never leave your device

How to use the Payment Calculator

Choose 'Find payment' or 'Find payoff term' at the top
Enter the loan amount and the annual interest rate
Enter the loan term in months, or the fixed monthly payment, depending on the mode
Read the solved payment or payoff term and the total interest below

Example

Input

$20,000, 6%, 60 months

Output

Payment: $386.66

Common errors & troubleshooting

The solved monthly payment looks far too high or too low. — Check the interest rate field is entered as a percent (6, not 0.06) and that the term is in months, not years.
'Find payoff term' shows an error that the payment never covers the interest. — A payment at or below the loan's monthly interest charge can never reduce the balance — increase the monthly payment above that interest-only amount.
Payoff term comes out as a fraction of a month. — Real payoff schedules round up to a whole final payment; the Payment Calculator shows the exact math and rounds the payment count up for you.
Numbers don't match a lender's quote exactly. — Lenders may round the payment to the cent differently or add origination fees — this tool solves the pure amortization math without extra fees.

Frequently asked questions

What does the Payment Calculator solve for?: Either a fixed monthly payment (given the loan amount, rate and term) or the payoff term in months (given the loan amount, rate and a fixed monthly payment). Switch modes at the top to choose which one you need.
How does the Payment Calculator compute the monthly payment?: It uses the standard amortized-loan formula: M = P × r × (1+r)^n ÷ ((1+r)^n − 1), where r is the monthly interest rate and n is the number of monthly payments. A 0% rate simply spreads the loan evenly across the term.
Why does the Payment Calculator say my payment will never pay off the loan?: If your monthly payment is less than or equal to that month's interest charge on the balance, the balance never shrinks. The Payment Calculator flags this so you can enter a payment above the interest-only amount.
Is the Payment Calculator's result exact?: No — it is an estimate only, not financial advice. Real loans may round payments, add fees, or compound interest slightly differently, so confirm final numbers with your lender.
Does the Payment Calculator upload my loan numbers anywhere?: No. Every calculation happens locally in your browser. The amount, rate, term and payment you enter are not sent to ArrayKit or anywhere else.
Can the Payment Calculator handle a 0% interest loan?: Yes. At 0% interest, the monthly payment is simply the loan amount divided by the term, and the payoff term for 'Find payoff term' is the amount divided by the payment, with no interest added.

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