Compound Interest Calculator - Free Online Investment Calculator
Calculate compound interest and investment growth over time. Set principal, rate, compounding frequency, and time period. See year-by-year growth. Free online calculator.
Enter values above to calculate compound interest.
What is Compound Interest Calculator?
Compound Interest Calculator is a free online tool that shows how an investment grows over time with compound interest. Enter your principal, annual rate, compounding frequency, time period, and optional monthly contributions to see the final amount and a year-by-year breakdown. Compound interest means you earn interest on your interest, accelerating growth over time.
How to Use Compound Interest Calculator
- Enter the initial principal amount
- Set the annual interest rate and compounding frequency
- Enter the time period in years
- Optionally add a monthly contribution to see its impact
Compound Interest Calculator Features
- Five compounding frequencies: annual, semi-annual, quarterly, monthly, daily
- Optional monthly contribution support
- Year-by-year growth table
- Shows principal, contributions, and interest separately
- Instant calculation, no server required
Compound Interest FAQ
What is compound interest?
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. This causes exponential growth over time, unlike simple interest which only applies to the principal.
How does compounding frequency affect growth?
More frequent compounding (e.g. daily vs. annually) results in slightly higher returns because interest is added to the principal more often, giving it more time to compound.
What is the Rule of 72?
The Rule of 72 is a quick estimate: divide 72 by the annual interest rate to find roughly how many years it takes to double your money. For example, at 6% annual rate, money doubles in about 12 years.