Tool 01

Investment growth calculator

Built for "what happens if..." thinking, with a simple main panel and deeper assumptions nearby.

Starting amount $ Contribution $ Annual return % 7% is a conservative real-return shorthand after inflation. Long-run S&P 500 total returns are often quoted around 10% to 12% nominal before inflation, depending on the period. Time period years

Advanced assumptions

Contribution increase % / yr Inflation assumption % Long-run U.S. CPI inflation has been roughly 3% per year since 1913, though any single decade can look very different. Read the inflation guide. Goal amount $

Future value $0 $0 in today's dollars

Total contributed$0

Investment growth$0

Final annual contribution$0

Contributed Growth

Goal timing

Goal timingNot reached

Investment calculator guide

Compound interest, contributions, and inflation-adjusted returns

The ClearWorth investment calculator estimates how a starting balance and recurring contributions could grow over time. It is built for long-term planning questions like "what will $500 a month become?" and "how much does inflation change the real value of my portfolio?"

Updated May 12, 2026. Educational estimate only.

Compound growth

The model applies your annual return as a monthly compounding rate, then layers in contributions based on the frequency you choose.

Contribution behavior

Weekly, semi-monthly, monthly, and annual contributions are normalized so different saving habits can be compared in one view.

Real return view

The inflation assumption shows what the ending balance could feel like in today-like dollars, instead of only showing nominal future dollars.

How to use this investment growth calculator

Start with your current invested balance, choose how much you plan to contribute, then pick a time horizon. A 30-year view is useful for retirement-style planning, while a 5- to 10-year view is better for medium-term goals where market risk matters more.

Use a nominal return if you enter inflation separately.
Use a real return, such as 7%, if you leave inflation at 0%.
Compare contribution changes before chasing a more aggressive return assumption.

What this calculator does not predict

Markets do not move in smooth lines. This calculator uses a steady average return to make the math understandable, but a real portfolio will have down years, tax consequences, fees, and behavior risk. Treat the output as a planning range, not a promise.

For retirement planning, pair this page with the Roth IRA vs. 401(k) guide and the savings benchmark guide.

What return should I use?

For broad stock-market planning, many people test 6% to 8% as a long-term real-return range and 9% to 12% as a nominal-return range. Conservative assumptions are usually better for planning than heroic ones.

Should I include inflation?

Yes, if you want to understand purchasing power. If your annual return is already inflation-adjusted, leave the inflation field at 0% to avoid double-counting.

Does this include taxes or fees?

No. Brokerage taxes, fund expenses, advisory fees, and withdrawal taxes are not modeled. Use the output as a gross planning estimate.

Why does increasing contributions matter so much?

Contributions do two things at once: they add principal and they give future returns more money to compound on. That is why a small recurring increase can become surprisingly large over decades.

Sources and research direction: Investor.gov compound interest calculator, Investor.gov on compound interest, and ClearWorth's inflation guide.