Future Value Calculator

What Future Value Actually Tells You

Future value answers a question almost everyone asks in some form: if I put money somewhere and leave it alone, what will it be worth later? The figure this calculator returns is the balance you would be holding at the close of the final period, assuming the rate you entered held steady the whole way through and nothing was taken back out.

Two quite different forces drive that ending number. Your starting balance compounds for every single period on the clock. Each deposit, by contrast, only earns growth for the periods that happen to come after it — a deposit made near the end barely has time to do anything. That asymmetry is the whole reason timing matters as much as amount, and why two people who contribute identical totals can finish with visibly different balances.

The result panel splits the ending balance into exactly those pieces — what you started with, what you deposited, and what growth contributed — because which of the three is doing the heavy lifting is usually the more interesting answer. In the example this page opens on, a $5,000 starting balance grows to $13,795.16 entirely on its own, while fifteen deposits of $250 add $6,282.26 between them. The two figures sum to the $20,077.41 on screen, and the split tells you immediately that the head start is worth more here than the contributions.

The Formula Behind the Numbers

None of this is a black box. Future value is the sum of two standard time-value-of-money expressions: one that carries a lump sum forward, and one that accumulates a stream of equal deposits.

The first term is straightforward compounding. The second is the future value of an annuity: the accumulated worth of every equal deposit, each one compounded for however many periods remained after it landed. The trailing (1 + i·T) is the only thing that separates an ordinary annuity from an annuity due — it hands each deposit one additional period of growth.

A zero rate breaks the annuity term, since it would divide by zero. The calculator handles that case directly rather than returning an error: with no growth, the ending balance is simply the starting amount plus every deposit made, or FV = PV + (PMT × N).

Worth knowing: the schedule underneath is not generated from the closed formula above. It is built the long way, period by period, adding interest and the deposit and carrying the balance forward. The two methods are computed independently and agree to the cent, which is a deliberate cross-check rather than a coincidence.

What Each Input Means

• Number of periods (N) — how many compounding steps the money passes through. This is a count of periods, not necessarily a count of years, which is the distinction that trips most people up.
• Starting amount (PV) — what is already in the account on day one. Leave it at zero if you are starting from nothing and want to see what the deposits alone will build.
• Interest rate (I/Y) — the rate earned in one period, entered as a percentage. If your periods are months, this is the monthly rate, not the annual headline figure.
• Periodic deposit (PMT) — the equal amount added at each step. Set it to zero to model an untouched lump sum. A negative number turns it into a regular withdrawal, which is a legitimate way to see how long a balance survives being drawn down.
• Deposit timing — whether each deposit lands at the start or the end of its period. End is the conventional default and matches most savings plans; the section below explains when it should be the other one.

The most common source of a wrong answer here is not a misunderstood field but a mismatched pair: a rate quoted per year sitting alongside a period count measured in months. Nothing in the arithmetic can detect that, so the result comes back confidently wrong.

Beginning vs. End of Period

Finance textbooks call these two arrangements an annuity due and an ordinary annuity, and the distinction is genuinely just a matter of when the money arrives. End-of-period deposits are the norm: you finish the month, then you transfer. Beginning-of-period fits situations where payment comes first — rent, most lease agreements, many insurance premiums, and payroll deductions that hit on payday rather than at month end.

Switching this page's opening figures from end to beginning moves the ending balance from $20,077.41 to $20,517.17, a difference of $439.76. The mechanism is simple: every deposit sits in the account one period longer, so every deposit collects one more round of growth. On a short horizon the gap looks like a rounding error. Stretch the same logic across a few hundred monthly deposits and it stops being negligible, which is why the setting is worth getting right rather than accepting whatever is preselected.

One useful property: with a positive rate, beginning-of-period always produces the larger number. If you flip the toggle and the result moves the other way, something else in the inputs has changed.

Periods Are Not Always Years

This is the single most frequent error in future value work, and it is worth spelling out. The calculator has no idea whether your periods are years, quarters, months or weeks. It only knows how many of them there are and what rate each one earns. Both figures have to describe the same unit of time.

To model $300 a month for ten years at a 6% annual rate, the conversion is: divide the rate by twelve, giving 0.5% per period, and multiply the years by twelve, giving 120 periods. That combination returns $49,163.80 — $36,000 of deposits and $13,163.80 of growth. Enter the same plan as 10 periods at 6% and the answer comes back as $3,954.24, because you have unknowingly asked about ten annual deposits of $300 rather than a hundred and twenty monthly ones.

The general rule: rate per period = annual rate ÷ periods per year, and N = years × periods per year. Quarterly means divide by four and multiply by four; weekly, fifty-two. If the two conversions do not use the same divisor, the answer is meaningless no matter how precise it looks.

Future Value vs. Present Value

These are one relationship read in two directions. Future value takes a sum and pushes it forward, layering growth on top. Present value takes a future sum and pulls it backwards, stripping the growth out to ask what you would need to hold today for that future amount to be the inevitable result.

The result card reports both deliberately. The present value figure is the entire plan — starting balance, every deposit, all the growth — expressed as one equivalent sum available right now. For the default inputs that comes to $7,276.98: a single deposit of that amount today, left completely alone at the same rate, arrives at exactly the same $20,077.41. It is a compact way of seeing what a savings plan is actually worth in current money rather than in future dollars.

That framing also makes it obvious why discount rates are contentious in practice. The higher the rate assumed, the smaller the present value of any future amount — which is precisely why arguments over pension valuations, settlement offers and long-dated contracts so often turn out to be arguments about a single percentage.

Reading the Period-by-Period Schedule

The headline number tells you where you land. The schedule tells you how, and it is usually the more instructive half of the page. Each row shows the balance at the start of the period, the deposit added, the growth earned, and the balance carried into the next row.

The pattern worth watching is the interest column. Early on it is small next to the deposit, and the balance climbs mostly because you are feeding it. Later the relationship inverts. Starting from nothing at 7% with $250 a period, the growth earned in a single period first overtakes the deposit itself at period 12, at $276.21. By period 30 the same period earns $1,528.56 while the deposit is still $250 — the account has quietly become the main contributor and you have become the minor one.

That crossover point is the practical argument for starting early, stated as a number rather than a slogan. It is also why the accompanying chart stacks the three components: watching the growth band overtake the deposit band is a much faster read than scanning a column of figures.

What This Calculator Leaves Out

Being clear about the boundaries matters more than adding decimal places. This tool assumes a fixed rate that never moves, deposits that never change, no withdrawals unless you enter a negative deposit, and no friction of any kind. Real accounts rarely behave that neatly.

• Inflation is ignored entirely. Results are nominal — future dollars, not today's buying power. The $20,077.41 in the default example would feel more like $12,886.93 after fifteen years of 3% inflation.
• Tax is not modelled. Interest in an ordinary savings or brokerage account is generally taxable in the year it is earned, which drags the effective rate below the one you entered. Tax-advantaged accounts behave differently again.
• Fees are absent. An expense ratio or account charge is best handled by subtracting it from the rate before you enter it.
• Volatility is invisible. A fixed 7% and an investment that averages 7% through real ups and downs do not produce the same outcome, and the difference grows with the size of the swings.

None of this makes the projection useless — it makes it a clean baseline. Treat the output as the answer to a precisely defined question, then adjust the rate downward for the frictions that apply to your own situation.

Frequently Asked Questions

What is the future value of money?

It is what a sum of money is expected to be worth on a specific date in the future, once interest or investment growth has been added to it. The idea rests on the fact that money available now can be put to work, so a dollar today and a dollar in ten years are not interchangeable. Future value puts a concrete number on that gap instead of leaving it as an intuition.

What is the formula for future value?

For a starting amount on its own, FV = PV x (1 + i)^N, where PV is the amount you begin with, i is the interest rate for one period as a decimal and N is the number of periods. When you also add an equal deposit each period, the future value of those deposits is added on: PMT x [((1 + i)^N - 1) / i], multiplied by a further (1 + i) if the deposits land at the start of each period rather than the end.

How do I calculate future value with monthly deposits?

Convert everything to months before you enter it. Divide the annual rate by 12 to get the rate for one period, and multiply the number of years by 12 to get the number of periods. A 6% annual rate over ten years becomes 0.5% per period across 120 periods, and $300 a month at those settings grows to $49,163.80. Leaving the rate at 6 and the periods at 10 answers a completely different question and gives $3,954.24, which is the classic version of this mistake.

What is the difference between an ordinary annuity and an annuity due?

An ordinary annuity puts each deposit at the end of the period; an annuity due puts it at the beginning. Choosing the beginning gives every single deposit one extra period of growth, so the ending balance is always higher when the rate is positive. With the values this page opens on, the two settings differ by $439.76 on an ending balance of roughly $20,000, which is small in percentage terms but far from nothing.

Is future value the same as compound interest?

They are closely related but not identical. Compound interest describes the mechanism, where interest is added to the balance and then earns interest itself in later periods. Future value is the result that mechanism produces by a given date, and it also covers the deposits you make along the way rather than just a single untouched sum.

Does this calculator account for inflation?

No. Every figure it returns is nominal, meaning it is stated in future dollars and ignores what prices do in the meantime. A balance of $20,077.41 in fifteen years would be worth about $12,886.93 in today's money at 3% annual inflation. If you want the answer in today's purchasing power, subtract your expected inflation rate from the rate you enter and read the result as real rather than nominal.

What happens if I enter an interest rate of 0%?

The calculator falls back to simple addition, because nothing compounds. The ending balance becomes the starting amount plus every deposit you made, and total interest comes out at zero. It is a useful sanity check: entering 0% should always return exactly the money you put in, and it is worth doing once to confirm the periods and deposit you typed are the ones you meant.

How is present value different from future value?

They are the same relationship read in opposite directions. Future value pushes a sum forward in time and adds growth; present value pulls a future sum backwards and strips growth out, answering what you would need today to end up with that amount. The result card shows both, so you can see that the plan on screen is equivalent to a single deposit of a much smaller sum made right now.

This calculator provides estimates for general informational purposes only and is not financial, investment or tax advice. Results are nominal figures based on the assumptions you enter and do not account for inflation, taxes, fees or investment volatility. Actual returns will vary. Consider speaking with a qualified financial professional before making decisions based on these projections.