Finance calculator
Annuity Calculator
Calculate annuity payment amount from a lump sum.
About the annuity calculator
The annuity calculator finds the monthly payment from a lump sum over a set period.
How to use this calculator
- 1
Enter lump sum
Enter the total annuity amount.
- 2
Enter rate and period
Enter the interest rate and payout period in years.
- 3
View results
See monthly payment, total paid, and interest earned.
How the calculation works
Payment = P × r(1+r)^n ÷ ((1+r)^n − 1) where r = monthly rate, n = total months. This is the same formula as loan amortization but in reverse.
Example: 100,000 at 5% for 20 years ≈ 660/month.
How financial calculations work
Most finance calculators use standard formulas: amortization for loans, compound interest for savings, and present/future value for investments. Results are estimates — actual terms may vary based on lender fees, credit score, taxes, and market conditions. Always consult a financial advisor for major decisions.
Understanding key financial terms
APR (Annual Percentage Rate) includes fees and interest. APY (Annual Percentage Yield) reflects compound interest. DTI (Debt-to-Income) ratio measures monthly debt payments against gross income. Lenders typically prefer DTI below 36%. CAGR (Compound Annual Growth Rate) smooths investment returns over time.
Important limitations
This tool provides a mathematical estimate based only on the values entered. It does not account for regulations, taxes, lender fees, market conditions, or individual circumstances. Results are for planning purposes only — consult a qualified professional for regulated, medical, financial, or construction decisions.
Frequently asked questions about annuity calculator
How accurate is the annuity calculator?+
The calculation follows the displayed formula and retains full numeric precision before formatting the result.
Can I use the result professionally?+
Use it as a planning estimate. Confirm regulated, medical, financial, or construction decisions with a qualified professional.