How do I find what percentage one number is of another?

Divide the first number by the second, then multiply by 100. For example, 30 is what % of 200? (30 ÷ 200) × 100 = 15%.

How do I calculate percentage increase or decrease?

Percentage change = ((New Value − Old Value) ÷ Old Value) × 100. A positive result is an increase; negative is a decrease.

Percentage Calculator

How to Use the Percentage Calculator

Select the type of percentage calculation you need from the dropdown, enter your values, and click Calculate. The result appears instantly. You can also share your calculation by copying the URL — it stores your inputs.

What is X% of Y? — Enter the percentage and the base number. Example: What is 15% of 200?
X is what % of Y? — Enter both numbers to find the percentage relationship. Example: 30 is what % of 200?
% change from X to Y — Calculate how much a value increased or decreased in percentage terms.

Percentage Formulas

1. Find X% of a Number

Result = (Percentage ÷ 100) × Number

Example: 15% of 200 = (15 ÷ 100) × 200 = 30

2. What Percentage is X of Y?

Percentage = (X ÷ Y) × 100

Example: 30 out of 200 = (30 ÷ 200) × 100 = 15%

3. Percentage Change

% Change = ((New − Old) ÷ Old) × 100

Example: Price rises from 80 to 100 → ((100 − 80) ÷ 80) × 100 = +25%

Worked Examples

Sales tax

A product costs $120. Sales tax is 8.5%. How much tax do you pay?

Tax = 8.5% of $120 = (8.5 ÷ 100) × 120 = $10.20. Total price = $130.20.

Exam score

You scored 68 out of 80 on an exam. What percentage did you get?

(68 ÷ 80) × 100 = 85%

Salary increase

Your salary goes from $45,000 to $48,600. What is the percentage increase?

((48,600 − 45,000) ÷ 45,000) × 100 = 8%

Discount

A jacket is $250 with a 30% discount. How much do you save?

Saving = 30% of $250 = $75. Price after discount = $175.

Frequently Asked Questions

How do I calculate a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 15% of 200 = (15 × 200) ÷ 100 = 30. Our calculator does this instantly.

What is the difference between percentage and percentage point?

A percentage describes a proportion (15% of 200). A percentage point is the arithmetic difference between two percentages — if interest rates go from 3% to 5%, that is a 2 percentage point increase, but a 66.7% increase in relative terms.

How do I reverse a percentage increase?

To find the original value before a X% increase, divide the current value by (1 + X/100). For example, a price of $130 after a 30% increase: original = 130 ÷ 1.30 = $100.

Can the percentage change be more than 100%?

Yes. If a value doubles, that is a 100% increase. If it triples, that is a 200% increase. A value going from 10 to 35 is a 250% increase.

How do I add a percentage to a number?

Multiply the number by (1 + percentage/100). For example, adding 20% to 150: 150 × 1.20 = 180. Or calculate 20% of 150 (= 30) and add it to 150.