Percentage Calculator

Three calculators in one — find a percentage of a number, express a value as a percentage, or calculate percentage increase and decrease. Results update instantly as you type.

%
Formula
Result = (Percentage ÷ 100) × Numbere.g. What is 15% of 2,000? → 300

Result

Enter values to see result

Quick tips

10% of entered value
25% of entered value
50% of entered value

About this tool

A fast percentage calculator covering the three most common calculations: finding what X% of a number is, expressing one number as a percentage of another, and calculating the percentage change between two values. Results update instantly as you type — no submit button needed.

The result card changes color to reflect the nature of the answer — neutral blue for standard percentage results, green for an increase, and red for a decrease. Quick-reference breakdowns below the result give you related values at a glance. All calculations run in your browser — no data is sent to any server.

How to use

1

Choose a calculator mode

Pick from three modes: 'X% of Y' to find a portion, 'X is what % of Y' to express a ratio, or '% Change' for increase or decrease.

2

Enter your values

Fill in the two number fields for your chosen mode. The result updates instantly as you type — no button needed.

3

Read the result

The result card shows the calculated answer. The color changes to green for an increase and red for a decrease in % Change mode.

4

Check the breakdown

Related percentage values appear below the main result, giving you quick context — fractions, complements, and more.

Frequently asked questions

Common questions about percentage calculations and how the tool works.

It finds the portion that X percent represents of the number Y. The formula is (X ÷ 100) × Y. For example, 15% of 2000 = 300. Use this to calculate discounts, tax amounts, tips, or any share of a total.

It expresses the number X as a percentage of Y. The formula is (X ÷ Y) × 100. For example, 75 is 25% of 300. Use this to find test scores, completion ratios, or market-share percentages.

The formula is ((New Value − Original Value) ÷ |Original Value|) × 100. A positive result is an increase; a negative result is a decrease. For example, going from 200 to 250 is a +25% increase; going from 200 to 150 is a −25% decrease.

Using |Original| rather than Original ensures correct sign behavior when the original value is negative. The sign of the change is determined by the direction (New − Old), not the denominator.

No. All calculations happen entirely in your browser using JavaScript. Nothing is sent to any server.