Compound Interest Calculator
Explore how an initial investment grows with regular compounding.
Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations retain full precision.
- Assumes a constant annual nominal rate, no deposits, withdrawals, taxes or fees.
Example Calculation
- Initial investment: 10000 $
- Annual rate: 5 %
- Time: 10 years
- Compounds per year: 12
$10,000 at 5%, compounded monthly for 10 years, grows to about $16,470.09.
Frequently asked questions
How do I use this calculator?
Enter initial investment, annual rate, time, compounds per year. The result updates automatically. Use Reset to restore the example values.
What method does it use?
A = P(1 + r / m)^(mt). Assumes a constant annual nominal rate, no deposits, withdrawals, taxes or fees.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.