Percentage Calculator

Calculate percentages instantly online for free. What is X% of Y? What percentage is X of Y? Calculate percent increase, decrease, and discounts.

Runs entirely in your browser — files never uploaded

Percentage (X)Number (Y)

Result

—

Value (X)Total (Y)

Percentage

—

Old value (X)New value (Y)

Change

—

How to use Percentage Calculator

1. Pick a calculation mode. Choose from "What is X% of Y?", "X is what % of Y?", or "Percentage change from X to Y".
2. Enter your numbers. Type values into the input fields — results update instantly as you type.
3. Read the result. The answer is displayed in large bold text below each section. No submit button needed.

How do I calculate a percentage of a number?

Enter the percentage and the number in the first section. For example, to find 15% of 200, type 15 and 200 — the result is 30.

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

Use the second section. Enter the part and the whole. For example, 25 is 50% of 50.

What is percentage change?

Percentage change measures how much a value increased or decreased relative to the original. The formula is ((new − old) / old) × 100.

What happens if I divide by zero?

The tool shows a dash (—) instead of a result whenever division by zero would occur.

Is my data sent to a server?

No. All calculations run entirely in your browser — nothing is transmitted.