Future Value Calculator

What the future value calculator does

The future value calculator shows what a sum of money will be worth later if you leave it to grow at a steady rate. You enter a present value, an annual growth rate, and a number of periods, and the tool projects the amount that sum will become, split into the money you started with and the growth on top.

Most people know money can grow, but few have a clear sense of how much a given amount turns into over ten, twenty, or thirty periods. A concrete figure lets you plan around a realistic target.

How future value is calculated

Future value equals the present value multiplied by one plus the rate, raised to the power of the number of periods. The starting amount grows by the rate in the first period, then that slightly larger balance grows by the rate again in the second period, and so on.

Because each period's growth is calculated on a balance that already includes earlier growth, the increases build on one another. Under simple growth, the same fixed amount is added every period. Under compound growth, the amount added rises each period because the base keeps expanding.

Over a few periods the two look similar. Over many periods they diverge sharply, which is why the future value of a long-held amount can be surprisingly large even at a modest rate.

The three inputs

• The present value is the amount you start with. Doubling it doubles the future value if the rate and periods stay the same.
• The annual growth rate is the percentage the balance grows each period. Small changes here have a large effect over long horizons, because the rate is applied again and again.
• The number of periods is how long the money grows. Extending the horizon usually changes the result more than people expect.

Reading the results

The tool shows the projected future value and the total growth earned, which tells you how much of the final amount came from your original money and how much from compounding. Over short horizons, most of the result is your starting sum. Over long horizons, the growth can rival or exceed what you began with.

The chart traces the value at the end of each period, and the curve steepens as compounding builds, with most of the growth arriving in the later periods.

Why the rate and the horizon matter

A one-point change in the rate might look trivial, but applied across twenty or thirty periods it makes a large difference to the final figure. Adding periods to the horizon also lifts the result sharply, because the extra periods carry the fully compounded balance forward.

A steady, believable rate held over a long horizon tends to produce a more reliable outcome than an ambitious rate that reality fails to deliver.

Using the results

The projection assumes the rate stays constant across every period, which real markets rarely do, so use it to compare scenarios:

• Lower the rate to a conservative figure for a cautious case, then raise it for an optimistic one. Reality usually sits somewhere between.
• Lengthen the horizon to see how much time alone adds with the rate unchanged.
• To measure real purchasing power, subtract expected inflation from the rate before entering it, so the future value is in today's money.

Common mistakes

• Entering an unrealistic rate. A rate possible in a single strong period is hard to sustain as a long-run average.
• Ignoring inflation. A nominal rate overstates real growth; netting off inflation shows what the future value will buy.
• Mismatching the rate and the period. If the rate is annual, each period must be a year. Mixing an annual rate with monthly periods produces a badly wrong answer.

Seeing what a lump sum becomes over a long horizon makes the case for investing early and leaving money to compound. Revisit the projection as your circumstances change.

This article is general information only and is not financial advice.

About This Future Value Calculator

Use this future value calculator to get an instant estimate based on the figures you enter. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.