Simple Interest Calculator

Calculate simple interest on a loan or deposit.

Interactive calculator
$
%
Result
Interest
$750
Total
$5,750
What it is

Simple interest is interest calculated only on the original principal — no compounding. Used for many short-term loans and bonds.

The formula

I = P × r × t (Principal × rate × time, no compounding)

Why it matters

Knowing the difference between simple and compound interest helps you spot when a deal is better (or worse) than it looks.

Worked examples

Try the example

Use the defaults above as a starting point — then adjust the inputs to match your situation.

Common pitfalls
  • Double-check the units on every input — most errors come from mixing units.
  • Round at the end, not in the middle of the formula.

Frequently asked questions

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