An ordinary annuity accumulates at period end
An ordinary annuity is a sequence of equal payments made at the end of equally spaced periods. Its future value is PMT × ((1+i)^n − 1)/i. Here i is the rate per payment period and n is the number of payments. No separate starting principal is included on this page.
Move the payments to the beginning
An annuity due shifts each payment one period earlier. Multiply the ordinary-annuity result by 1+i. The calculator presents both values so the timing difference is visible. With twelve payments of $100 at 1% per period, the ordinary result is $1,268.25 and the annuity-due result is $1,280.93.
Convert the rate before entering it
For a 12% nominal annual rate compounded monthly and monthly payments, i is 1%. For a 12% effective annual rate, the equivalent monthly rate is (1.12)^(1/12) − 1 instead. Period counts must be whole numbers here. At a zero periodic rate, both timing options equal payment multiplied by number of payments.
Questions about this calculation
How can I check the inputs behind the result?
Open “Show calculation & assumptions” for the formula and timing conventions, then inspect the breakdown. Export CSV to keep the last calculated inputs and numerical results together.
Does this include taxes or changing market returns?
No tax calculation or variable market-return path is included. The task-specific assumptions above describe the scope. Calculated values are conditional on the inputs, not personalized recommendations.
Learn more
Start with the step-by-step future value formula guide.
Open the formula guide →How to calculate future value · Spreadsheet calculations · All learning guides
Use these figures to explore assumptions. Actual interest, returns, fees, taxes and purchasing power can differ.