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Financial Interstate

Time Value of Money Calculator

Money you have today and money you'll have later aren't worth the same amount. This calculator estimates the future value of a starting balance plus regular contributions — or works backward to the amount you'd need today to hit a target.

In present-value mode, this is the target amount you want in the future.

A long-run estimate. Returns are not guaranteed.

Added each period. Set to 0 for a lump sum only.

Estimated future value

Total contributions
Estimated growth

Enter your numbers above to see an estimate.

How this works

In future-value mode the calculator applies the standard compounding formula FV = PV·(1 + r)n + PMT·[((1 + r)n − 1) / r], where r is the rate for each period and n is the number of periods. Your annual rate is divided by how often you contribute, and contributions are assumed to be added at the end of each period.

Present-value mode runs the same relationship in reverse to find the lump sum needed today to reach your target, given your contributions and rate.

A 0% rate is handled cleanly — it simply sums your contributions.

What this does not include

This is an estimate. It does not account for taxes, fees, inflation, market volatility, or returns that change from year to year. Real investments don't grow in a smooth line.

It assumes a single constant rate and steady contributions. Life is rarely that tidy — treat the result as a directional guide, not a promise.

Like this tool? The case studies go deeper.

Each issue works through a real money decision — the kind these calculators only start to answer.

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