Compound Interest Calculator
Final Amount
13,535
Total Interest Earned
8,535
Total Invested
5,000
Year
Total Amount
Interest Earned
Total Invested
1
5,524
524
5,000
2
6,102
1,102
5,000
3
6,741
1,741
5,000
4
7,447
2,447
5,000
5
8,227
3,227
5,000
6
9,088
4,088
5,000
7
10,040
5,040
5,000
8
11,091
6,091
5,000
9
12,252
7,252
5,000
10
13,535
8,535
5,000
About
The Compound Interest Calculator applies the formula A = P(1 + r/n)^(nt) to show how an investment grows over time. Choose from daily, monthly, quarterly, semi-annual, or annual compounding. The results include the final amount, total interest earned, and a year-by-year growth table so you can see the power of compounding in action.
How to use
- 1 Enter your starting principal (initial deposit or investment).
- 2 Enter the annual interest rate or APY.
- 3 Set the investment period in years.
- 4 Choose a compounding frequency (daily compounds fastest).
- 5 The final balance, interest earned, and growth table appear instantly.
- What is compound interest and how is it different from simple interest?
- Compound interest calculates interest on both the original principal and the accumulated interest from previous periods — interest earns interest. Simple interest only calculates on the original principal. For example, $1,000 at 10% for 3 years: simple interest gives $300; compound interest (annual) gives $331 — a $31 difference that grows dramatically over longer periods.
- How does compounding frequency affect the final amount?
- More frequent compounding produces a higher final amount because interest is added to the principal more often, so each subsequent calculation has a larger base. Daily compounding gives the highest result, followed by monthly, quarterly, semi-annual, and annual. The difference is significant over long periods — on $10,000 at 8% over 30 years, daily compounding yields about $1,000 more than annual compounding.
- What is the Rule of 72?
- The Rule of 72 is a quick mental formula for estimating how long it takes an investment to double at a given interest rate: divide 72 by the annual interest rate. For example, at 8% annual return, 72 ÷ 8 = 9 years to double. At 6%, it takes 12 years. It is a useful approximation for annual compounding — verify with this calculator for exact values.