ToolAlto Guide
How to Calculate a Percentage: Simple Examples
Learn the basic percentage formulas for finding a percentage of a number, percentage change, discounts, and more.
Find a percentage of a number
To find X percent of Y, convert X to a decimal by dividing by 100, then multiply by Y. For example, 20% of 50 is 0.20 × 50 = 10.
Find what percentage one number is of another
Divide the part by the whole and multiply by 100. For example, 25 out of 200 is 12.5%.
Calculate percentage change
Subtract the old value from the new value, divide by the old value, and multiply by 100.
Calculate a discount
Multiply the original price by the discount percentage to find the discount amount, then subtract it from the original price.
Use a calculator for quick checks
For repeated calculations, a percentage calculator reduces manual arithmetic and helps you check your result.
Try the free ToolAlto Percentage Calculator
Use the tool directly in your browser for a quick result.
Open Percentage Calculator →