Payment Calculator
Adjust the inputs below. Results update as you type.
How it works
PMT = PV × r / (1 − (1+r)^−n). For monthly payments, divide annual rate by 12 and multiply years by 12. Bi-weekly payments: use 26 periods/year—this creates one extra monthly-equivalent payment annually and saves years of interest. Balloon loans have a large final payment; factor it in as a future value. Early payoff always saves interest proportional to remaining balance.
Input guidance
- Principal is the amount financed after down payment and trade-in.
- Convert APR to the period rate that matches your payment schedule.
- Term should be the number of payments, not only years.
The formula
Solve the amortization formula for the payment M given the loan amount, rate, and term, or solve for the term given a fixed payment: n = −ln(1 − P·r/M) / ln(1+r).
Worked example
A $10,000 balance at 12% APR: paying $250/month clears it in about 50 months. Raising the payment to $400/month clears it in about 28 months and saves hundreds in interest.
More examples to test
- $18,000 at 9% for 48 months: monthly payment and total interest.
- Same loan at 36 vs 60 months: compare payment vs lifetime interest.
How to interpret results
Lower payments from longer terms usually raise total interest. Compare both before choosing.
When this can be inaccurate
Fees, balloons, and variable rates are outside a level fixed-payment model.
Change history
- July 2026: Published amortizing PMT path with period-conversion notes.
Site-wide corrections also appear on the corrections log.
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Frequently asked questions
Can I solve for payment or for time?+
Both. Enter a term to find the required monthly payment, or enter a payment to find how many months it takes to pay off the balance.
Why does a higher payment save so much?+
Larger payments knock down the principal faster, so less interest accrues each month. The savings compound over the life of the loan.
What if the payment is below the interest?+
If your payment is smaller than the monthly interest, the balance never falls — it grows. The payment must exceed the first month's interest to make progress.
How should I use this result?+
Treat it as a planning estimate. Compare at least two realistic scenarios, then confirm with statements, quotes, or a qualified professional before acting.
How often should I refresh assumptions?+
Refresh whenever rates, income, costs, or policy limits change materially, and before making irreversible commitments.