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Future Value Calculator

See what your money grows to with compound interest and monthly contributions — then what it actually buys in today's dollars, adjusted for live inflation.

Monthly compoundingInflation-adjusted real valueContributions vs growth split

A big future balance only matters in today's dollars — so we show both the nominal total and its real buying power after live inflation.

2.3×

$130k invested ($10k + $500/mo) grows to $300,851 at 7% over 20 years

57%

of that final balance is pure compound growth — money you never deposited

$160k

what that $300,851 actually buys in today's dollars after live CPI inflation

What this means for your money

Compound interest rewards patience — and inflation quietly taxes the headline number.

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The power of compounding

Compound growth is exponential, not linear. Early years barely move the needle; by year 20–30 the growth dwarfs your contributions. In the default scenario the final year alone adds about $20,000 of growth — more than three years of deposits.

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Nominal vs. today's dollars

A big future number is misleading if you ignore inflation. We deflate the nominal balance by the live FRED CPI rate so you see real buying power — at 3.2% inflation, $300,851 in 20 years is worth about $160,235 in today's money.

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Starting early vs starting late

Time matters more than amount. At 7%, money doubles roughly every 10 years — so one extra year on the front end is worth far more than a bigger deposit. Delaying the start costs you the most valuable, fully-compounded years.

How the Future Value Calculator Works

Formula

FV = PV × (1 + r)ⁿ + PMT × (((1 + r)ⁿ − 1) / r) Real FV = FV ÷ (1 + i)^years Where: PV = Initial deposit (present value) PMT = Monthly contribution r = Monthly return rate (annual rate ÷ 12) n = Total months (years × 12) i = Annual inflation (live FRED CPI)
1

Enter your initial deposit

The lump sum you're starting with — can be $0 if you're starting fresh.

2

Set monthly contributions

How much you add each month. Even $50/mo compounds significantly over decades.

3

Choose your return rate

Expected annual return. ~7% is a conservative real estimate; ~10% is the S&P long-run nominal average.

4

Pick your time horizon

How many years the money grows. Longer horizons multiply the result exponentially.

5

Read both numbers

Your nominal future value and its value in today's dollars, deflated by the live CPI inflation rate.

This calculator uses the standard future-value formula with monthly compounding: contributions are added at the end of each month and the whole balance grows at your annual rate divided by 12.

Crucially, it doesn't stop at the nominal number. It deflates the result by the live FRED Consumer Price Index inflation rate over your horizon, so you see what the balance is actually worth in today's purchasing power — the figure that determines what your money can buy.

Historical context: the S&P 500 has averaged roughly 10% nominal (about 7% after inflation) over the long run, and US prices have risen ~3.3% per year on average since 1914. We pull the current CPI live so the inflation adjustment reflects today's economy, not a stale assumption.

Frequently Asked Questions