A walkthrough, end to end.
- 1
Enter a starting lump sum, monthly deposit (optional), annual rate, and number of years.
- 2
The calculator returns the future value, total contributions, and total interest earned.
- 3
Use it for any scenario where money compounds — not just savings or investing.
Future value (general formula)
Future Value combines compound growth on the principal with the future value of an annuity (regular deposits). With monthly compounding, it's the sum of both. The function works whether you have only a lump sum, only deposits, or both.
What you can do with this.
Future value of a single lump sum
$10,000 left at 6% for 20 years grows to ~$32,071. The lump-sum future value formula (FV = P·(1+r)^n) is the financial bedrock — every long-term planning calculation builds on it.
Future value of an annuity (deposits)
$500/month at 7% for 30 years = ~$612,000 future value. Powerful illustration of how regular contributions compound — the principal contributed is just $180K but growth adds $432K.
Combined: lump sum + deposits
$50K starter + $750/mo at 7% for 25 years = ~$870K. Most real scenarios involve both — a kickoff balance plus ongoing additions. The calculator handles the combined case.
Goal-setting (work backward)
Want $1M in 30 years? Plug in target FV, time, rate — see what monthly contribution gets you there. Useful for retirement targets, college savings goals, etc.
Inflation impact
$500K future value at 3% inflation over 25 years has the purchasing power of ~$240K today. Use the inflation calculator to convert nominal future values to real purchasing power.
Compounding frequency effect
More frequent compounding (monthly vs annual) increases FV by 1–3% over 20+ years at typical rates. The calculator uses monthly by default — matches most real savings/investment products.
Real vs. nominal returns
Use 7% real return for inflation-adjusted future purchasing power; 10% nominal return for raw dollar amounts. Don't mix — always project in real OR nominal, never both.
FV calculator 2026 — what's current
Most retirement projections continue to use 7% real (10% nominal) for stock-heavy portfolios. Recent firm-level forecasts (Vanguard, BlackRock) suggest 4–6% real for the next 10 years — plan conservatively.
Frequently asked.
Compound interest typically refers to a single lump sum growing. Future value is more general — it covers lump sum + regular deposits, lump sum alone, or deposits alone.
Nominal for raw dollar amounts (matches advertised investment returns). Real for purchasing power planning (subtract inflation). Always be clear which you're using.
Compounding magnifies tiny differences. 1% extra rate over 30 years adds 30%+ to the future value. Watch your fees on managed accounts — they directly subtract from compounding rate.
No. Calculations run entirely in your browser.