Compound Interest Calculator
Compute the future value of money growing at compound interest.
Calculator
Use the Compound Interest Calculator
Result
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Formula
A = P × (1 + r/100)^t
Step-by-step
- 1
Enter the principal
The starting amount.
- 2
Enter rate and time
Annual rate and number of years.
Worked example
Example input: principal: 1000, rate: 5, years: 10
Result: 1628.89
Related tools
- Simple Interest
Flat interest, no compounding.
- Exponential Growth
Continuous growth model.
Frequently asked questions
What formula does this calculator use?
A = P × (1 + r/100)^t, with interest compounded once per year. For example, 1000 at an annual rate of 5% for 10 years grows to 1000 × 1.05^10 ≈ 1628.89.
Does it support monthly or daily compounding?
No — this calculator compounds annually only. Monthly compounding pays slightly more because interest starts earning interest sooner; the general form is P × (1 + r/n)^(n × t) with n periods per year.
How is compound different from simple interest?
Simple interest always applies the rate to the original principal: 1000 at 5% pays exactly 50 per year, reaching 1500 after 10 years. Compound interest applies the rate to the running balance and reaches about 1628.89 in the same case.