Percentage Calculator
Find a percentage of a number, or what percent one number is of another.
Guide: Percentage Calculator
Solve common percentage problems fast: find a percent of a number, or express one number as a percent of another. Useful for discounts, grades, taxes, and data analysis. Percentages are ratios scaled to 100, which makes human communication easier than carrying fractions everywhere—yet the underlying math is still multiplication and division.
Percentage change vs percent of
“Percent of” scales a base value. Percent change compares old and new values: (new − old) / old × 100%. Use the right mental model for your task.
A 50% increase followed by a 50% decrease does not return you to the original number because the second move uses a larger base.
Retail and tip mental checks
Ten percent of a price is one decimal shift; twenty percent doubles that. Use the tool when sleep-deprived checkout lines demand certainty.
Stacked discounts (20% then 10%) are not the same as 30% off; they multiply as complements of one.
Data and reporting
When a dashboard says “conversion rate,” confirm whether the denominator is sessions, users, or orders—percentages hide the base easily.