Growth & Return
Annuity Calculator
Calculate the payment for a loan or an annuity.
Annuity Calculator
All math runs locally in your browser. Nothing is uploaded.
How it works
An annuity is a series of equal payments. This calculator finds the payment that pays off a present balance over a fixed number of periods at a fixed rate — the same math behind car loans, mortgages and annuitized retirement income.
The payment is higher than a simple division by periods because each payment must also cover the interest accrued on the remaining balance.
Formula
PMT = PV · r / (1 − (1 + r)−n)
PV = present balance, r = rate per period, n = number of periods. With r = 0 the payment is simply PV / n.
Worked example
Example: a $20,000 balance at 0.5% per month for 60 months. PMT = 20000 × 0.005 / (1 − 1.005^−60) = $386.66 per month, for a total of $23,199.33 including interest.
WORKED EXAMPLE — DEFAULT INPUTS
What to know
Early payments in an amortizing loan are mostly interest; later payments are mostly principal. Over a 60-month loan at 6% annual, the interest share starts near half of the early payments and falls to almost nothing at the end.
That shape matters for two decisions. If you plan to prepay a loan, extra payments kill the remaining interest most effectively early on. And if you are comparing offers, the payment alone hides the total interest — multiply the payment by the number of periods to see the full cost of the loan.
This calculator covers an ordinary annuity, where payments land at the end of each period, which is how most loans work. Annuities due, where payments start immediately, are slightly different and are common in rent and insurance.
Whether you are pricing a loan or planning withdrawals, run the payment at two or three different rates before you commit; the rate is the single biggest lever on what each period costs you.
FAQ
What rate should I enter?
The rate per period. A 6% annual mortgage paid monthly means 0.5% per period and n counts months.
Is the payment rounded for real loans?
Lenders round to the nearest cent, which slightly changes the final payment count. This tool gives the mathematically exact payment.
Does this include escrow or insurance?
No. It covers principal and interest only; escrow, taxes and insurance are separate.
Can I use it in reverse for savings?
Yes. Enter a future savings target as PV and a rate, and the payment tells you the monthly deposit needed to reach it.