Percentage Calculator
Percentage calculator X%
Three common percentage problems. The solution appears right below the form you calculate.
Type 1. Find X% of Y
Formula: (X × Y) / 100. Example: 15% of 200.
Type 2. X is what percent of Y?
Formula: (X / Y) × 100%. Example: 30 out of 200.
Type 3. Change from X to Y
Find the difference and the rate (Y − X) / X × 100%, then decide whether it is an increase or a decrease.
The calculator above handles the most common percentage questions: the percent of a number, what percent one value is of another, and percentage change.
Formulas used
Percent = a / b × 100%
p% of b = p · b / 100
Change = (new − old) / old × 100%
- A positive change is an increase, a negative change is a decrease.
- Percentage points are not the same as percent change.
Worked example
What percent is 45 of 180?
45 / 180 × 100% = 25%
Enter the same values in the calculator above to see every step of the solution.
How to use the calculator
- Choose the type of calculation and enter the two values.
- Press the calculate button. The result appears instantly.
- Read the step-by-step solution, rendered with KaTeX, to check your own work.