Future Value Calculator
See what a lump sum and any regular contributions grow to over time. Set your starting amount, expected return, time horizon, and (optionally) a monthly or yearly deposit, then choose how often interest compounds. You get the future value, the interest earned, an inflation-adjusted figure, and a full year-by-year breakdown.
Formula
Worked example
$10,000 at 7% for 20 years with monthly compounding grows to about $40,387. Add $200 a month and the contributions add roughly $104,000 more, for a future value near $144,000, of which about $90,000 is compound interest.
How future value works
Future value tells you what money is worth at a later date once it has earned a return. A starting lump sum is multiplied by one plus the periodic rate, raised to the number of periods. Because each period's interest is added to the balance and then earns interest itself, growth is exponential rather than linear, so small changes in the rate or the time horizon produce large changes in the final amount. This calculator also handles a level stream of contributions, treating them as an annuity whose future value is added on top of the grown lump sum.
Contributions, compounding and timing
Regular deposits often matter more than the starting amount. Each contribution grows for the time remaining until the end, so earlier deposits earn far more than later ones. Compounding frequency sets how often interest is added: monthly compounding grows slightly faster than annual at the same nominal rate. Timing matters too, deposits made at the start of each period (an annuity due) earn one extra period of growth compared with end-of-period deposits, which is why the timing option nudges the result up or down. The calculator converts your nominal rate and compounding into an effective rate per contribution period so every combination stays mathematically consistent.
Nominal versus real value
The headline future value is nominal, the actual number of dollars you will hold. Inflation erodes purchasing power over time, so a large future balance buys less than the same number today. Turn on the inflation adjustment to discount the future value back into today's money: a 7% nominal return with 3% inflation behaves roughly like a 4% real return for purchasing-power purposes. Always use realistic, after-fee return expectations rather than best-case years, and treat the result as a projection, not a guarantee.
Effect of compounding frequency on $10,000 at 7% for 20 years
| Compounding | Growth factor | Future value |
|---|---|---|
| Annually | 3.8697 | $38,697 |
| Quarterly | 4.0064 | $40,064 |
| Monthly | 4.0387 | $40,387 |
| Daily | 4.0546 | $40,546 |
More frequent compounding adds a little extra growth at the same nominal rate.
Frequently asked questions
What is the future value formula?
For a single lump sum, FV = PV × (1 + i)^n, where PV is the present value, i is the rate per period, and n is the number of periods. With regular contributions you add the future value of an annuity: PMT × [((1 + i)^n - 1) / i]. This calculator combines both and adjusts the rate for your chosen compounding frequency.
How do regular contributions change the result?
Each contribution grows for the time left until the end, so early deposits compound for longer and contribute far more than later ones. Adding even a modest monthly amount to a lump sum can dwarf the starting balance over a long horizon, which is why the contribution and frequency fields are included.
What is the difference between beginning and end of period contributions?
End of period (an ordinary annuity) assumes you deposit at the close of each period, the common default. Beginning of period (an annuity due) assumes you deposit at the start, giving every contribution one extra period of growth, so the future value is slightly higher.
Does this account for inflation?
The headline figure is the nominal future value. Turn on the inflation adjustment to also see the value in today's money, which discounts the future sum by your expected inflation rate so you can judge real purchasing power.