Simple Interest Calculator
Get the interest earned or charged when interest applies only to the original principal.
Quick answer
Enter the principal, annual percentage rate and time. The result shows simple interest and the principal plus interest.
Formula used
Simple interest = principal × annual rate × years. Total value = principal + simple interest.
Worked example
On $10,000 at 6% simple interest for three years, interest is $1,800 and the total is $11,800.
How to interpret the result
Many real loans and savings accounts use compounding, fees or payment schedules instead of pure simple interest. Check the product terms.
Sources and methodology
Investor.gov compound interest calculator · Consumer Financial Protection Bureau: saving. Sources explain general concepts; ToolGemini calculations use only the values you enter and the formula shown above.
Related calculators
Browse money calculators · Savings goal calculator · Compound interest calculator
Frequently asked questions
What is the difference between simple and compound interest?
Simple interest applies only to the original principal. Compound interest can also earn or charge interest on prior interest.
Can time include part of a year?
Yes. Enter a decimal such as 1.5 for eighteen months.
Does this include fees?
No. The result includes only principal, rate and time.