📈 Compound Growth Calculator

The most important calculator in personal finance. Set your % of paycheck, watch what 30–40 years of compounding looks like.

Gross monthly income$5,800
~$70k/yr default. Slide to your situation.
% of paycheck invested15%
Includes employer match. 15% is the rule of thumb for retiring at 65.
Years investing40 yrs
Expected annual return7%
7% is the long-run global equity average. 5% conservative; 9% optimistic.
Monthly contribution
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Total contributed
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Final value
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🎯 What this means

📊 Growth Curve

The Magic of Time

Hover the chart to see year-by-year. Notice how the line curves up dramatically in later years — that's compound growth. Most of your final wealth comes from gains on previous gains, not your contributions. Starting early is more valuable than contributing more.

👤 Starts at 25

Invests $500/mo for 10 years (until 35), then stops contributing forever. At 65 (with 7% return)…

~$558,000

👤 Starts at 35

Invests $500/mo for 30 years straight (until 65). At 65 (with 7% return)…

~$566,000

Starting 10 years earlier and contributing for 1/3 the time produces nearly the same outcome as starting 10 years later and contributing for 30 years. Time > amount.