Percentage Calculator
Free percentage calculator — find X% of a number, what percent X is of Y, and percentage increase or decrease between two values.
The three percentage questions
- X% of Y — multiply:
Y × X/100. (18% of 2,500 = 450) - X is what % of Y — divide:
X/Y × 100. (45 of 180 = 25%) - Percent change —
(new − old)/old × 100. Positive = increase, negative = decrease.
Frequently asked questions
How do I calculate X% of a number?
Multiply the number by X and divide by 100. For example, 18% of 2,500 = 2,500 × 18 ÷ 100 = 450. The first row of this calculator does it for you.
How do I calculate percentage increase or decrease?
Percent change = (new − old) ÷ old × 100. Going from 1,200 to 1,500 is (300 ÷ 1,200) × 100 = +25%. A negative result means a decrease.
How do I reverse a percentage?
To find the original value before an X% increase, divide by (1 + X/100). For example, if a price is ₹1,180 after adding 18%, the original was 1,180 ÷ 1.18 = ₹1,000.
Is this percentage calculator free?
Yes — free, instant and private. All three calculations run locally in your browser.