Investor Tool

Compound Interest Calculator

Visualize the long-term power of compounding and see when your money starts doing the hard work.

UPGRADE
Decision Inputs

Your starting amount of money. E.g., $10,000

Amount added each month. Higher contributions grow your portfolio faster. E.g., $500

Time horizon in years. Longer periods allow more compounding. E.g., 30

Expected annual return percentage. Historical stock market average is ~7-10%. E.g., 8

Analysis Result

Calculation Pending

Adjust your inputs and click "Calculate Growth" to see your results.

Risks & Limitations

  • Returns are never linear; actual market performance will fluctuate significantly year-to-year.
  • Inflation will reduce the future purchasing power of the calculated amount.
  • Taxes (capital gains or income) are not included in this deterministic model.

Next Steps

Data Sources
  • Standard Compound Interest Formula
Model Assumptions
  • Monthly compounding
  • Fixed annual return rate
  • No taxes or fees
Last UpdatedFebruary 2025