Finance & Money
Simple Interest Calculator
I = P × r × t
Educational estimates only. Not medical, legal, tax, or financial advice.
Guide: Simple Interest Calculator
What it does
Computes interest as principal × rate × time without compounding.
How to use it
Enter principal, annual rate, and time in years, then calculate.
Formula
Interest = P × r × t; total = P + interest.
Example
$5,000 at 4% simple interest for 3 years → $600 interest, $5,600 total.
FAQs
When is simple interest used?
Some short-term notes and teaching examples; most savings products compound.
How is time entered?
Use years as a decimal (e.g., 18 months = 1.5 years) unless the form specifies otherwise.
Can interest accrue daily on a simple-interest loan?
Some products accrue on a daily basis but still use simple interest rules—follow your promissory note.