📈 Compound Interest Calculator

See how a starting balance and regular monthly contributions grow when returns are reinvested. Small differences in rate or time make a big difference over decades.

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How this is calculated

Returns are compounded monthly and contributions are added at the end of each month. Taxes, fees and inflation are not included, so treat the result as a nominal, pre-tax estimate.

Frequently asked questions

What return should I assume?

High-yield savings pay the current savings rate; diversified stock funds have historically returned more but with large swings. Using a conservative rate gives a safer plan.

What is the rule of 72?

Divide 72 by the annual return to estimate how many years it takes to double your money.

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