Simple Interest Calculator
Calculate simple interest earned or owed on a principal amount. Compare with compound interest to see the difference.
Simple Interest
I = P × r × t
$
%
yrs
$0Total Amount
$0
Interest Earned
$0
Principal
Simple vs. Compound Interest
Simple Interest: I = P × r × tP = Principal · r = Rate (decimal) · t = Time (years). Total = P + I
With simple interest, you earn the same amount each period. With compound interest, you earn interest on your interest, so growth accelerates over time.
On $5,000 at 5% for 3 years: Simple = $750 interest. Compound (monthly) = $802 interest. The difference grows larger over longer periods.