How do I calculate what percentage X is of Y?

Divide X by Y and multiply by 100. Example: 45 is what percentage of 180? 45 ÷ 180 = 0.25 × 100 = 25%. So 45 is 25% of 180.

How do I calculate percentage change?

Subtract the old value from the new value, divide by the old value, and multiply by 100. Formula: ((New - Old) / Old) × 100. Example: price changed from 80 to 100: ((100 - 80) / 80) × 100 = 25% increase.

How do I add a percentage to a number?

Multiply the number by (1 + percentage/100). To add 20% to 150: 150 × 1.20 = 180. To subtract 20%: 150 × 0.80 = 120.

How to Calculate Percentages Online

Calculate any percentage instantly with our free Percentage Calculator. Supports percentage of, percentage change, percentage increase/decrease, and more.

Steps

Choose the calculation type

Select the type of percentage calculation you need: 'What is X% of Y?' for finding a portion; 'X is what % of Y?' for finding the percentage relationship; 'Percentage change from X to Y' for comparing two values; or 'Increase/decrease X by Y%' for applying a percentage to a base value.

Enter your values

Type the numbers into the appropriate fields. The calculator accepts whole numbers and decimals. For currency calculations, enter the amount without currency symbols — just the numeric value.

View the result

The result appears instantly as you type. The calculation also shows the formula used so you understand how the result was reached.

Use the result

Copy the result or note it for your use. For percentage changes, the direction (increase or decrease) and the absolute change amount are both shown alongside the percentage.

Percentage Calculations in Everyday Life

Percentage calculations appear constantly in daily life: calculating tips at restaurants (15–20% of the bill), working out discounts during sales (30% off = multiply price by 0.70), understanding tax rates (VAT/sales tax added to the pre-tax price), calculating interest on savings or loans, understanding exam scores (correct answers ÷ total questions × 100), tracking progress towards goals (current ÷ target × 100), and comparing values across different scales. Our calculator handles all these scenarios with the correct formula for each type of percentage problem.

Percentage vs Percentage Points: A Common Confusion

A percentage point is an absolute difference between two percentages, while a percentage change is a relative difference. If an interest rate rises from 2% to 3%, it has risen by 1 percentage point but by 50% (1/2 × 100). These are different statements and can lead to confusion in financial and news reporting. When a government reports that unemployment fell by 2 percentage points (from 8% to 6%), that is not the same as saying unemployment fell by 2% (which would mean from 8% to 7.84%). The distinction matters significantly for interpreting statistics accurately.