Compound Interest Calculator
Calculate how compound interest grows your money over time.
Compare daily, monthly, quarterly, and yearly compounding.
Final Amount
Compound interest is calculated using the formula:
A = P × (1 + r/n)^(n×t)
Where:
- A = Final amount
- P = Principal (initial investment)
- r = Annual interest rate (as a decimal)
- n = Number of times interest compounds per year
- t = Number of years
Interest earned is simply: Interest = A - P
Compounding frequency matters:
- Daily (n=365): Best returns, used by many savings accounts
- Monthly (n=12): Common for CDs and some bonds
- Quarterly (n=4): Common for corporate bonds
- Yearly (n=1): Simplest form
For example, $10,000 at 7% for 20 years:
- Compounded yearly: $38,696.84
- Compounded monthly: $40,387.39
- Compounded daily: $40,551.97
The more frequently interest compounds, the more you earn — but the difference decreases as frequency increases.