Payment Calculator
Calculate the fixed periodic payment for any financed amount, interest rate, and exact number of payments — for monthly, biweekly, or weekly schedules.
How It's Calculated
Formula
\text{Payment} = \dfrac{P \times r \times (1 + r)^n}{(1 + r)^n - 1}This calculator works out the fixed periodic payment for any financed amount — a loan, purchase plan, or other fixed-rate installment obligation — given the annual interest rate and the exact number of payments. Unlike calculators that ask for a term in years, this one asks for the payment count directly, since that's sometimes the number you actually have (a payment plan quoted as "36 payments," for example). If you instead know your term in years and want the payment count derived for you, use Repayment Calculator. This calculator is deliberately generic — it has no vehicle-, home-, or purchase-specific fields — for a specialized case, use Mortgage, Auto Loan, or Personal Loan Calculator.
Worked Examples
60 monthly payments: $20,000 financed, 7.5% annual rate
- Periodic rate r = 0.075 / 12 = 0.00625
- Payment = 20000 × 0.00625 × (1.00625)^60 / ((1.00625)^60 − 1) ≈ $400.76
- Total of all payments = $24,045.51; total interest = $4,045.51
One payment: $1,000 financed, 5% annual rate, 1 monthly payment
- With only one payment, the entire principal plus one period's interest is due at once
- Payment = 1000 × (1 + 0.05/12) ≈ $1,004.17
Frequently Asked Questions
How is this different from Repayment Calculator?
This calculator asks for the exact number of payments directly. Repayment Calculator instead asks for a term in years and a frequency, and derives the payment count for you. Use whichever matches the number you actually have — a payment plan quoted in exact payments, or a loan quoted in years.
Can I use this for a mortgage, auto loan, or personal loan?
The underlying fixed-rate amortization math is the same one those specialized calculators use, so the numbers here are mechanically correct for any fully-amortizing fixed-rate obligation. This tool doesn't add mortgage-, auto-, or personal-loan-specific extras — for those, use the dedicated calculators.
What interest rate should I enter?
Enter the nominal annual interest rate as stated (e.g. 7.5 for 7.5%) — not an APR that bundles in fees, and not a rate already divided down to a per-payment rate. This calculator converts the annual rate to a per-period rate internally based on your chosen payment frequency.
What if I enter 0% interest?
The payment becomes a straight-line division of the financed amount across the number of payments, with $0 total interest — a valid boundary case, not an error.