How to Calculate Percentages (With Easy Examples)
Percentages appear everywhere — discounts, test scores, tips, interest and statistics. Yet the three main types of percentage question trip people up. This guide breaks each one down with a simple formula and example so you'll never be unsure again.
1. What is X% of Y?
Multiply the two together after dividing the percentage by 100.
Result = (X ÷ 100) × Y
Example: 20% of 150 = (20 ÷ 100) × 150 = 30.
2. X is what percent of Y?
Divide the part by the whole, then multiply by 100.
Result = (X ÷ Y) × 100
Example: 30 is what percent of 150? (30 ÷ 150) × 100 = 20%.
3. Percentage increase or decrease
Find the difference, divide by the original, multiply by 100.
Change = ((New − Old) ÷ Old) × 100
Example: from 200 to 250 = ((250 − 200) ÷ 200) × 100 = +25%.
Step-by-step: use the calculator
- Open the Percentage Calculator.
- Pick the calculation you need from the three boxes.
- Enter your numbers and click Calculate.
Frequently Asked Questions
How do I add a percentage to a number?
Find the percentage of the number, then add it on. To add 15% to 200: 15% of 200 = 30, so 200 + 30 = 230.
How do I remove a percentage (like a discount)?
Subtract instead of adding, or use our Discount Calculator for prices.
What's the difference between percentage and percentage points?
Percentage points are the absolute difference between two percentages (e.g. 20% to 25% is 5 points), while percentage change (25%) is relative to the starting value.
Is the calculator free?
Yes, and it runs entirely in your browser.
Can I use decimals?
Yes — enter any decimal or whole number.
Try the Percentage Calculator