Annuity Payment Calculator
PMT = P · r / (1 − (1+r)^(−n)). Payment that fully amortizes a principal over n periods at rate r.
Result
Payment per period
$599.55
Total: $215,838 · interest: $115,838.
- Principal$100,000.00
- Periodic rate0.5000%
- Periods360
- Payment$599.55
- Total payments$215,838.19
- Total interest$115,838.19
Step-by-step
- PMT = P × r / (1 − (1+r)^(−n))
- = 100000 × 0.005000 / (1 − (1+0.005000)^(−360))
- = $599.55 per period.
How to use this calculator
- Enter principal.
- Enter periodic rate (monthly = annual / 12).
- Enter number of periods.
About this calculator
The amortization formula gives the constant payment that pays off a principal P over n periods at periodic rate r, mixing principal and interest. Used for mortgages, car loans, fixed annuities, bond coupons. For a $100k mortgage at 6% (0.5% monthly) over 30 years (360 months): payment ≈ $599.55/mo.
Frequently asked
Always match the period. Monthly payments use monthly rate (annual / 12) and number of months.
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