Future Value Calculator

Future value is the amount a present sum or series of contributions will grow to in the future once compound interest is applied. It lets you estimate how much capital you will accumulate after a given number of years of saving. It is a core concept of financial mathematics used in retirement and investment planning.

It uses FV = PV * (1 + r)^n + PMT * (((1 + r)^n - 1) / r), where PV is the principal, PMT is the monthly contribution, r is the monthly rate (annual / 12) and n is the number of months. The first part grows the principal, the second the accumulating contributions. Interest compounds monthly.

The principal is a one-off amount you hold today that works for the whole period. The monthly contribution is a recurring amount added each month, so your capital grows steadily. Contributions are optional — you can compute the future value of a single lump sum by entering zero here.

Total contributions is the full amount you actually paid in from your own pocket: the principal plus all monthly contributions (PMT * number of months). It excludes interest. Comparing total contributions with the future value shows how much of the final capital is your input versus earned interest.

The total gain is the difference between the future value and total contributions — the earnings from compound interest. It shows how much your money earned by itself. The longer the period and the higher the rate, the larger the share of gain in the final capital.

The calculator compounds interest monthly, dividing the annual rate by 12 and capitalising each month. This compounding is typical of deposits, savings accounts and regular investment plans. With monthly compounding the effective annual rate is slightly higher than the nominal rate.

Time is the most powerful variable in compounding. Each extra year lets interest grow from a larger base, so future value rises exponentially rather than linearly. Starting to save a few years earlier can therefore produce a much higher final capital than larger contributions over a shorter time.

No. The result is a nominal gross value, with no inflation adjustment and no deduction of capital gains tax (19% in Poland). To judge the real purchasing power of future capital, use a purchasing-power calculator and subtract the applicable tax from the gain.

At 0% no interest accrues, so the future value simply equals total contributions: the principal plus all monthly contributions. The total gain is then zero. This is a useful baseline scenario showing how much you would accumulate with no interest at all.

No. The calculator assumes a constant rate for the whole period, which is not guaranteed for market investments — actual returns fluctuate. The result is informational and educational; when planning, consider several return scenarios and consult an adviser.