1,000 at 5% for 3 years
1,000 × 0.05 × 3 = 150 interest, 1,150 in total.
Simple Interest Calculator
Calculate simple interest and the total amount from a principal, an annual rate and a time in years, months or days.
Result
Enter your values and select Calculate to see the result.
Runs in your browser — nothing you enter is sent to a server.
How the Simple Interest Calculator works
Simple interest is paid only on the original amount (the principal), not on interest already earned. Enter the principal, the annual rate and the time in years, months or days. Days use a 365-day year.
Formula
I = P × r × t
Where:
- P
- Principal
- r
- Annual rate as a decimal (5% = 0.05)
- t
- Time in years
The total amount is P + I.
Examples
Frequently asked questions
What's the difference between simple and compound interest?
Compound interest also earns interest on previous interest, so it grows faster over time. Use the Compound Interest Calculator for savings accounts and investments.
Information:
Good to know
Results are estimates for planning. They aren't financial advice, and your bank or lender may round, charge fees or calculate interest differently.
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