Future Value Calculator
Calculate the future value of your investments with regular monthly contributions. See how your money grows over time with compound growth.
A future value calculator projects what today's money — plus any recurring contributions — will be worth at a specific point down the road. The base formula for a lump sum is FV = PV · (1 + r)^n, where PV is what you have today, r is the periodic return, and n is the number of periods. Add a stream of deposits and you need the future-value-of-an-annuity formula layered on top: FV_annuity = PMT · [((1 + r)^n − 1) / r]. Our calculator combines both into a single answer so you can see the full picture without juggling spreadsheets.
The most powerful lever in this equation is time, followed by rate, with contribution amount a distant third for long horizons. That's why compounding frequency matters at the margin: the same 7% nominal rate compounded annually, monthly, or continuously produces different effective annual yields — 7.00%, 7.23%, and 7.25% respectively. Over 40 years that gap translates to tens of thousands of dollars. When you're comparing a CD at 5.0% APY to a savings account at 4.9% APY, the APY already bakes in the compounding, so you can compare directly; when you're comparing a 5.0% APR (stated annual) vs a 5.0% APY, the APR is the lower effective yield.
Where does the future value calculator show up in real planning? Retirement — how much will my 401(k) be worth at 65? Education — will my 529 cover tuition? Goal-setting — I want $500,000 by age 50, what do I need to save? Lump-sum investments — if I drop $50,000 in an index fund and never touch it, what's that in 30 years? This tool handles all of them. Remember: the output is nominal dollars, and it's educational only, not financial advice.
Quick answer: Starting from $10,000 and adding $500/month for 20 years at a 7% return, your future value is roughly $300,000 — with $120,000 from your contributions and $180,000 from compounded growth. This future value calculator projects the final balance for any starting amount, rate, horizon, and monthly contribution.
Inputs
Quick presetsThe lump sum you have today, before any future deposits. Enter 0 if starting from scratch.
Expected annualized return. 4-5% for HYSA, 6-7% real for diversified stocks, 10% nominal for long-run S&P 500.
Time horizon. The longer the runway, the more compounding dominates contributions.
Amount auto-deposited each month. Computed with monthly compounding to match most brokerage products.
Results
How to use this calculator
Four inputs drive the calculation. **Present value** is the starting balance — the amount you have today, before any future deposits. Leave it at $0 if you're starting from scratch. **Annual interest rate** is your expected yearly return, as a percentage. Use 4–5% for high-yield savings, 6–7% real for a diversified stock portfolio, or 10% nominal for the historical US large-cap average. Don't be optimistic — a conservative rate gives a more defensible projection.
**Number of years** is the time horizon. The longer the horizon, the more dramatic the compounding effect, but also the more uncertain the return assumption. **Monthly contribution** is the amount you'll add every month on autopilot. The calculator uses monthly compounding under the hood, which approximates most brokerage and savings products well. The output breaks the final balance into three components: the total future value, your total cash contributions over the period, and the interest (the gap between those two) — the "money earned by your money." Run a few scenarios to see how much a 1% rate change or a 5-year delay actually costs you.
Worked examples
Sofia, 30, investing for retirement
Sofia has $15,000 in a brokerage account and can contribute $800/month into a target-date index fund. She wants to see her projected balance at age 65 assuming a 7% long-term return. Inputs: present value $15,000, rate 7%, years 35, monthly $800. The calculator projects a future value of roughly $1.49 million, of which her own contributions total about $351,000 — meaning compound growth delivered $1.14 million of the balance. If she bumps the monthly to $1,000, the ending balance rises to about $1.78 million, a $290,000 boost from just $200/month more.
David's 529 plan for his newborn
David opens a 529 college savings plan for his newborn with $5,000 and plans to add $250/month for 18 years. Assuming a 6% return (a bit conservative since the glide path shifts to bonds), the calculator shows about $112,800 at age 18. Of that, $59,000 came from contributions and $53,800 from growth. If state tuition inflation runs 5% annually, today's $30,000/year tuition becomes roughly $72,000/year in 18 years, meaning the 529 covers about 1.5 years — a useful reality check for top-up savings plans.
Maya's late-start catch-up at 45
Maya, 45, has $120,000 in a rollover IRA and realizes she's behind. She commits to maxing out a $2,000/month contribution between 401(k) and IRA for the next 20 years, assuming a 6.5% blended return. Inputs: present value $120,000, rate 6.5%, years 20, monthly $2,000. The calculator projects about $1.40 million at age 65 — $480,000 from contributions and roughly $920,000 from compounding. If she delays just 5 years (starting at 50 instead), the same plan ends near $880,000, a loss of over $500,000. The cost of waiting is the clearest lesson the tool surfaces.
Frequently asked questions
What's the future value formula?
For a lump sum: FV = PV · (1 + r)^n. For a stream of equal payments: FV = PMT · [((1 + r)^n − 1) / r]. If you have both a starting balance and ongoing contributions, add the two results. Our calculator does this automatically using monthly compounding.
How much does compounding frequency matter?
Less than most people think — but not zero. A 7% nominal rate compounded annually gives 7.00% effective yield; monthly gives 7.23%; daily gives 7.25%; continuous gives 7.25%. Over 40 years on a $100,000 lump sum, the gap between annual and monthly is about $70,000. Compare APY to APY whenever possible.
Is this calculator in nominal or real dollars?
Nominal. That means the output does not account for inflation. To convert to today's purchasing power, divide the result by (1 + inflation)^years, or subtract your expected inflation rate from the return rate before calculating. A 7% nominal return minus 3% inflation ≈ 4% real.
What return rate is realistic for stocks?
Historically the S&P 500 has delivered about 10% nominal / 7% real annualized over the very long run, with plenty of volatility. Many planners assume 6–7% nominal for conservative retirement projections. Overestimating return is the single most common way these projections mislead — build in a margin of safety.
Can I use this for an annuity (stream of payments)?
Yes. Set present value to 0 and enter your periodic contribution as monthly. The future-value-of-annuity math is built in. If you want to see the present value of that same stream, use the annuity calculator instead.
How is FV used in retirement planning?
It's the single most important calculation behind any retirement projection. You estimate your starting balance, contribution rate, return assumption, and years to retirement, then compute FV. Comparing that to your target (usually 25× annual expenses under the 4% rule) tells you whether you're on track or need to save more.
What about taxes on the growth?
The calculator shows pre-tax growth. In a Roth account, growth and withdrawals are tax-free, so the output is your real ending balance. In a Traditional 401(k)/IRA, withdrawals are taxed as ordinary income, so net balance is lower. In a taxable brokerage, dividends and capital gains create a 0.5–2 percentage point annual drag.
How do I account for uneven contributions?
This calculator assumes a constant monthly contribution. If your actual pattern varies (e.g., year-end bonuses, raises over time), either use an average, or run several calculations for each phase and add them. For rising contributions, a spreadsheet or specialized tool handles it more accurately.