Future Value Calculator

Future value is the dollar amount a sum of money grows to by a chosen future date, once compounding interest or investment returns are applied. A $5,000 deposit today earning 7% annually, compounded monthly, grows to about $10,048 in 10 years. The calculator breaks the final balance into how much came from your starting amount, your periodic payments, and interest earned.

An ordinary annuity adds each payment at the end of a period, which is the standard convention for things like bond coupons and retirement payouts. An annuity due adds each payment at the start of the period, so every payment earns one extra period of interest. For a $500 monthly payment at a 6% annual rate over 20 years, the annuity due ends about $1,155 higher than the ordinary annuity.

The calculator converts your annual rate to a per-period rate by dividing by the number of periods per year, then multiplies the years by that same number to get total periods. A 6% annual rate compounded monthly means a 0.5% period rate applied over 120 periods for a 10-year horizon. More frequent compounding earns slightly more, because each smaller period puts returns to work sooner.

With a 0% rate the calculator skips the compounding formula entirely. Future value equals your starting amount plus the number of periods times your payment per period. No interest is earned, so the result is purely the cash you put in.

The calculator returns no result when total periods exceed 100,000, which is roughly daily compounding for more than 273 years. Past that point the (1 + r)^n term approaches floating-point overflow and the output becomes unreliable. Every practical retirement and savings case, even 50 years compounded daily, stays well inside this limit.