Percentage Calculator
This free percentage calculator solves percent of a number, percentage increase, percentage difference, and “what percent is X of Y” (percentage finder) problems instantly — including everyday tip and margin-style percent checks.
The three percentage formulas
What is X% of Y? Multiply Y by X divided by 100:
X is what percent of Y? (percentage finder) Divide X by Y and multiply by 100:
Percent change / percentage increase or difference from X to Y:
Common uses: tips, margins, and discounts
Use this tool as a quick tip calculator (e.g. 15–20% of a bill), a margin calculator for markup, or a percentage increase calculator for raises and investments. For sales tax specifically, try our Sales Tax Calculator.
Frequently Asked Questions
How do I calculate percentage increase?
Subtract the old value from the new value, divide by the old value, and multiply by 100. This percentage increase calculator does that for you.
What is the difference between percent change and percentage difference?
Percent change is relative to a starting value (increase or decrease). Percentage difference often compares two values relative to their average — use the change formula here for from→to problems.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. That is the percentage finder mode of this calculator.
Can I use this as a tip calculator?
Yes — enter the bill as Y and the tip percent as X in “what is X% of Y” to get the tip amount.