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Compound Interest: Why Starting Early Changes Everything

Compound interest is the most powerful force in personal finance. Learn why starting 10 years early nearly doubles your wealth and why delay is so costly.

By FlowFund TeamJune 28, 20263 min read

The Most Powerful Force in Finance

Compound interest: interest earning interest on interest. The longer it runs, the more dramatic the effect.

The Math

Simple interest: $10,000 at 7% = $700/year. After 30 years: $31,000 total.
Compound interest: $10,000 at 7% reinvested. After 30 years: $76,123 total.
Difference: $45,123 earned entirely from interest on interest.

Rule of 72

Divide 72 by annual return to estimate doubling time:
7% return: 72 / 7 = 10.3 years to double.
10% return: 72 / 10 = 7.2 years to double.

$10,000 at 7%: $20,000 at year 10, $40,000 at year 20, $80,000 at year 30, $160,000 at year 40.

The 22 vs 32 Comparison

$5,000/year at 7% from age 22 to 65: approximately $1,142,000.
$5,000/year at 7% from age 32 to 65: approximately $554,000.

The 10-year head start nearly doubles the outcome.

For Freelancers

Variable income tempts many to delay investing. Every year of delay costs more than the previous year because compounding potential grows. Start small. Start now.

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