Annuity Calculator
Calculate annuity future value, payment, or present value instantly.
📊 What is an Annuity?
An annuity is a series of equal periodic payments made over a fixed number of periods at a constant interest rate. The word "annuity" comes from the Latin annuus (annual), but annuities can have monthly, quarterly, or annual payment intervals. Annuities appear throughout personal finance: mortgage payments, car loans, lease payments, pension income, and structured settlement payments are all annuities in the mathematical sense.
There are two fundamental types based on when payments occur. In an ordinary annuity (also called annuity-immediate), payments occur at the end of each period. Most loans and bonds are ordinary annuities. In an annuity-due, payments occur at the beginning of each period - rent, insurance premiums, and lease payments typically follow this pattern. An annuity-due has a slightly higher value than an equivalent ordinary annuity because each payment earns one extra compounding period.
In the insurance and retirement context, an annuity is a contract with an insurance company. You pay a lump sum (or series of premiums), and the insurer promises a guaranteed income stream for a fixed period or for life. This calculator focuses on the mathematical calculation of ordinary and annuity-due cash flows and can solve for future value, present value, or the periodic payment given the other variables.
📐 Annuity Formula
All annuity calculations derive from the time-value-of-money principle: a dollar today is worth more than a dollar in the future. The annuity formula aggregates the compounded future value (or discounted present value) of each individual payment. Annuity-due is always greater than ordinary annuity by exactly (1+r), reflecting the one extra period of compounding for each payment.