🚀 Future Value (FV) Calculator
A future value calculator for a lump sum plus recurring monthly contributions, showing how much of the result each part actually produced.
What Future Value (FV) Calculator Does
Future value answers what a sum becomes after a period of compounding, and it splits into two parts that behave very differently. A lump sum grows by itself. Regular contributions each compound for however long is left after they arrive — so the first deposit does most of the work and the last one does almost none.
That asymmetry is the single most important thing about long-horizon saving, and it is why time matters more than amount. $10,000 left alone at 7% becomes about $38,700 in twenty years. Adding $500 a year on top — $10,000 more in total — takes it to roughly $59,200, because those later contributions have not had long to grow.
Compounding frequency matters less than people expect but is not nothing. Monthly compounding beats annual at the same nominal rate, because interest starts earning interest sooner. This calculator compounds monthly, which matches how most savings products actually work.
And every projection here is nominal. It says nothing about what the money will buy, which is a separate question and usually the one that matters — a 7% return with 3% inflation is about 4% in real terms.
How to Use Future Value (FV) Calculator
- Enter your starting present value (lump sum)
- Input monthly recurring additions (PMT)
- Enter the expected annual interest rate and investment duration in years
- View your total future value, interest profit, and wealth growth multiple
Formula Used by Future Value (FV) Calculator
Future value of a lump sum and of regular contributions
FV = PV(1 + r)ⁿ + PMT × [((1 + r)ⁿ − 1) ÷ r]
- PV
- the amount you start with
- PMT
- the regular contribution each period
- r, n
- the rate and number of periods — monthly here, so an annual rate is divided by 12
Worked example
$10,000 at 7% a year for 20 years, with and without $500 added annually.
- Lump sum alone: 10,000 × 1.07²⁰ = $38,697
- Contributions: 500 × ((1.07²⁰ − 1) ÷ 0.07) = $20,497
- Total: 38,697 + 20,497
Result: $59,195. The $10,000 you started with grew by $28,700; the $10,000 added along the way grew by only $10,500, because it arrived late.
What $10,000 becomes at different rates
Lump sum only, no further contributions. Nominal figures, before inflation and tax.
| Rate | 10 years | 20 years | 30 years |
|---|---|---|---|
| 3% | $13,439 | $18,061 | $24,273 |
| 5% | $16,289 | $26,533 | $43,219 |
| 7% | $19,672 | $38,697 | $76,123 |
| 10% | $25,937 | $67,275 | $174,494 |
How to Read Your Result
Starting earlier beats saving more
The exponent in the formula is time. Ten years of growth on an early pound does more than a much larger sum added near the end, which is why the practical advice is almost always to start rather than to wait until you can afford more.
Nominal is not real
Every figure here ignores inflation. To see what the money would actually buy, run the result through an inflation calculator, or simply use a real rate — the nominal return minus expected inflation — which turns 7% into roughly 4% and produces a far soberer number.
A constant rate is a modeling convenience
Markets do not deliver the same return each year, and the order of good and bad years matters when you are also contributing or withdrawing. A smooth projection is useful for understanding the shape of compounding and is not a forecast of any particular outcome.
Limitations & Accuracy Notes
- Assumes a constant rate compounded monthly. Real returns vary year to year, and sequence matters.
- No tax, platform fees or fund charges — fees compound against you exactly as returns compound for you.
- Nominal figures throughout; inflation is not applied.
- Contributions are assumed regular and unchanging; it does not model increases in line with earnings.
- Nothing here is financial advice.
Frequently Asked Questions
What is Future Value (FV)?
What is the difference between Ordinary Annuity and Annuity Due?
What is the difference between future value and present value?
Does compounding frequency change the result?
Should I adjust for inflation?
What does this assume about the return?
Can I model regular contributions?
Is this investment advice?
References & Further Reading
- US SEC Investor.gov — compound interest calculator — The official reference implementation of this arithmetic