Percentage Calculator

Most percentage questions are one of three shapes.

Notes

  • Percentage change is not symmetric. Going from 100 to 120 is +20%, but 120 back to 100 is -16.6667%.
  • Change from zero is undefined and is reported as an error rather than as infinity.

Common questions

What is the difference between percentage points and percent?
A rate moving from 5% to 7% is a rise of 2 percentage points, but a 40% increase. Both are correct — they answer different questions.
How do I remove a percentage that has already been added?
Divide rather than subtract. To strip 8% tax from $108, divide by 1.08 to get $100. Subtracting 8% would leave $99.36.