About the Compound Interest Calculator
Compound Interest Calculator does the math for you. Enter your values in the format shown and the result appears immediately — no spreadsheets, no formulas to remember, and nothing is uploaded to a server.
How Compound Interest works
Compound interest earns interest on both the principal and previously earned interest:
A = P × (1 + r/100)^t
where P = principal, r = annual rate (%), and t = years (compounded annually).
Worked example — ,000 at 5% for 10 years:
- Growth factor: 1 + 5/100 = 1.05
- Compound over 10 years: 1.05^10 ≈ 1.62889
- Final amount: 1000 × 1.62889 = ,628.89
- Interest earned: 1628.89 − 1000 = 8.89
How to use
- Enter your values as shown in the input box.
- The result is calculated instantly.
- Click Copy to use it.
Examples
| Input | Result |
|---|---|
00, 5%, 10 yr | ,628.89 (8.89 interest) |
00, 8%, 5 yr | ,346.64 (,346.64 interest) |
Common uses
- Quick everyday math.
- Double-checking figures fast.
- Schoolwork and homework.
- Finance, health and planning.
Frequently asked questions
Is my data uploaded?
No — the calculation runs entirely in your browser, so your data stays private.
Is it free?
Yes — completely free with no sign-up.