Percentage calculator: of, increase, and decrease

A percentage calculator answers the questions that show up in homework, invoices, and sales: what is 18% of 250? What percent did revenue grow? What is the price after a 30% off sale?

Steps

1. Open the percentage calculator.
2. Pick the problem type (of / change / reverse, depending on the fields shown).
3. Enter the numbers.
4. Read the result and copy it into your sheet or invoice.

For checkout math, you may also want the discount calculator or tip calculator.

Everyday examples

• Tax and tip on a bill
• Score: “I got 42 of 50—what percent?”
• Markup or markdown on inventory
• Year-over-year growth for a report

Tips

• Percent of and percent change are different formulas—match the wording of the problem
• Round money to two decimals after the calculation, not before
• Watch for “increase by 20%” vs “increase to 20%”

Limits

The tool does arithmetic only. It does not pull live tax rates for your city or sync with accounting software.

CTA: Open the percentage calculator.