Compound growth calculator

See what steady contributions, time, returns and fees do to a balance. Your numbers, the math shown.

This is the calculator behind the chart in Before I learned to invest, I learned to save. Change any number and the result updates instantly. The defaults match the 2026 IRA limit.

Before65 · Compound growth calculator

Starting age

Stop at age

Starting balance$

Yearly contribution$

Return per year%

Yearly fee%

Return is before fees. Try 6%, 8% and 10% to see how much the assumption matters.

Add the $1,100 catch-up contribution from age 50

You put in

–

Balance at the end

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Share that is growth

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BalanceWhat you put in

Hypothetical illustration, not a forecast and not advice. Assumes one contribution at the end of each year, a constant return, returns reinvested, the fee charged on the balance once a year, and no taxes or withdrawals. Nominal dollars, not adjusted for inflation. Real markets don’t move in a straight line. For 2026 the IRA contribution limit is $7,500, plus $1,100 at age 50 and older, and income limits apply to Roth contributions (IRS).

Two things worth trying: move the starting age from 20 to 30 and watch what ten years costs, then set the fee to 1% and compare it with no fee.