Compound Interest
Future value with monthly contributions and compounding.
Future value
$124,379.03
Total contributed
$53,000.00
Total interest
$71,379.03
Assumes monthly compounding and end-of-month contributions. For estimates only.
Informational only; verify critical results independently.
How to use
- Enter your starting balance (principal) if you have one.
- Enter the nominal annual interest rate and how long the money will grow.
- Choose compounding frequency (e.g. monthly or annually) if the tool offers it.
- Optionally add a recurring monthly or yearly contribution.
- Review future value and total interest or growth—compare to not investing.
- Try conservative and optimistic rates to bracket uncertainty (not a forecast).
Examples
- $5,000 at 5% compounded monthly for 10 years with no contributions
- $200/month at 4% for 20 years starting from $0
- $1,000 lump sum at 6% APY for 15 years
- Compare annual vs monthly compounding on the same rate and term
- Model a starter emergency fund growing at 3% for 5 years
- See growth on a one-time bonus invested for 25 years at 7%
FAQ
- How is compounding applied?
- Interest is added on each compounding period; future periods earn on the larger balance.
- Are results after tax?
- No. Tax on interest, dividends, or withdrawals depends on account type and country rules.
- Is this a guaranteed return?
- No. The rate you enter is hypothetical. Markets and bank rates change.
- What about inflation?
- Results are nominal. Subtract expected inflation mentally for a rough “purchasing power” view.
- Contributions at beginning or end of month?
- Depends on the tool’s setting. Check the label; small timing differences add up over long horizons.
- Where is it calculated?
- In your browser; numbers are not sent to our servers.
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Last updated: 2025-09-11