What the Future Value Calculator does
This future value calculator projects what a starting amount plus regular contributions will grow to at a rate of return you choose. It supports any compounding frequency, contributions weekly to yearly, paying in at the start or end of each period, and an annual step-up for contributions that rise with your income - and it shows the balance year by year, split between what you paid in and what growth added.
The rate is your assumption, not a promise. The page is built to make that assumption visible: the effective yearly rate, the year-by-year table and a chart of balance against money contributed, so you can see how much of the result depends on growth.
How to use it
- Enter a starting amount, a regular contribution, or both, and how often you contribute.
- If you plan to raise your contributions every year, enter the percentage. Tick the start-of-period box if you pay in at the beginning of each month or year.
- Enter the yearly rate of return, how often it compounds and the number of years.
- Read the future value and how much of it is growth, then check the year table - and try a lower rate to see a more cautious result.
Reading the results
Growth earned is the future value minus everything you paid in. Over long periods it often exceeds the contributions, which is compounding at work; over short periods most of the balance is your own money.
The rate you enter is taken as constant. Real investments vary from year to year, and a sequence of poor years near the end can leave you well short of a smooth projection with the same average.
The result is in future money. With 3% inflation, a sum twenty years away buys roughly 55% of what it would today; the inflation impact calculator converts it back to today's money.
Worked example: 5,000 plus 300 a month for 20 years
Someone starts with 5,000 and adds 300 at the end of each month for 20 years, earning 7% a year compounded monthly. The monthly rate is 0.07 / 12 = 0.583333% and there are 240 months, so the growth factor is 1.0058333^240 = 4.038739.
The starting amount grows to 5,000 x 4.038739 = 20,193.69. The contributions grow to 300 x (4.038739 - 1) / 0.0058333 = 156,278.00. Together: 176,471.69.
The saver paid in 5,000 + 300 x 240 = 77,000, so 99,471.69 - more than half the final balance - is growth. At 5% instead of 7%, the same plan ends at about 136,873, which is why testing a lower rate is worth doing.
Formulas and scoring rules
- Rate per contribution period
i = (1 + r / m)^(m / p) - 1r annual rate, m compounding periods a year, p contributions a year.- Lump sum
FV = PV x (1 + i)^n- Level contributions, end of period
FV = C x ((1 + i)^n - 1) / iAt the start of each period, multiply by (1 + i).- Annual step-up
contribution in year k = C x (1 + s)^(k - 1)With a step-up the balance is built period by period rather than from one formula.- Growth earned
growth = FV - starting amount - all contributionsMoney shown to the nearest whole unit; calculations are not rounded.
Why contributing at the start matters
Paying in at the start of each period gives every contribution one extra period of growth. At 7% with monthly contributions the difference is about 0.58% of the contributions' future value - small in a year, noticeable over decades. It is the same distinction as an ordinary annuity versus an annuity due.
A step-up has a bigger effect than it first appears. Raising a 10,000 monthly contribution by 5% each year for 15 years roughly doubles the monthly amount by the end, and the later, larger contributions have less time to grow - so the future value rises by less than the extra money paid in would suggest.
Limitations: what the result does not prove
- It uses a constant rate. Actual returns vary, and the order of good and bad years changes the outcome even with the same average.
- Taxes, fund charges and inflation are not deducted. Use a net rate if you want them included, or the fee and inflation calculators to see their effect.
- Years are whole numbers; the balance is reported at the end of each year.
- It is a projection, not financial advice or a forecast of any particular investment.
Privacy: where your data goes
Everything you paste, type or drop is processed in this browser tab. It is not uploaded, logged, stored or sent to analytics. Session recording and tag-manager scripts are switched off on this page.
Standards and sources
Frequently asked questions
How is future value calculated with monthly contributions?
Each contribution grows for the number of months left until the end. Adding them up gives C x ((1 + i)^n - 1) / i, where i is the monthly rate and n the number of months. 300 a month for 20 years at 7% compounded monthly grows to 156,278.
What rate of return should I use?
Use a rate that matches what the money is actually in: a deposit rate for savings, a cautious long-run figure for a diversified fund, and a lower figure if fees and taxes are taken out. Running two or three rates shows the range of plausible outcomes.
Does compounding frequency make much difference?
Less than the rate itself. 7% compounded monthly is 7.23% a year effective, against 7% compounded yearly - over 20 years that is a few percent of the final balance, not a transformation.
What does increasing contributions each year do?
It models saving a fixed share of a rising income. The calculator raises the contribution at the start of each new year by the percentage you enter and builds the balance month by month, so the table shows the higher contributions as they happen.
Is future value the same as compound interest?
Compound interest is the mechanism; future value is the result. A compound interest calculator usually focuses on a lump sum, while this page adds regular contributions, their timing and annual increases.
How do I see the result in today's money?
Divide by (1 + inflation)^years, or enter the future value in the inflation impact calculator. At 3% inflation over 20 years, 176,472 in the future is worth about 97,700 in today's money.
Last reviewed by the A2Z.Tools team against the sources listed above.
