Percentage Calculator — Free Online

Work out percentages: X% of Y, what percent X is of Y, and percentage change. 100% in your browser — free, no sign-up.

How to

  1. 1Choose the calculation type.
  2. 2Enter the two numbers.
  3. 3Read the result instantly.

What can it calculate?

Three of the most common percentage questions: what is X% of Y, X is what percent of Y, and the percentage change from one number to another. Pick the mode and enter two numbers.

How it works

All three formulas run in your browser as you type, so you get the answer instantly with no rounding surprises. Nothing is sent anywhere.

When to use it

Calculate a discount or tip, work out a tax or markup, find a test score as a percentage, compare two figures, or measure growth and decline between two values.

The formulas

X% of Y = (X ÷ 100) × Y. X is what percent of Y = (X ÷ Y) × 100. Percentage change from A to B = ((B − A) ÷ A) × 100. Example: 20% of 150 = 30; 30 is 20% of 150; and a change from 150 to 180 is +20%.

Percentage change explained

Percentage change is the difference between two values relative to the first: (new − old) ÷ old × 100. A positive result is an increase, a negative one is a decrease — useful for prices, metrics, and results over time.

FAQ

What calculations does it support?+

Three: what is X% of Y, X is what percent of Y, and the percentage change from one number to another.

How is percentage change calculated?+

As (new − old) ÷ old × 100. A positive result is an increase, a negative one a decrease.

Is my data sent anywhere?+

No. Everything is computed in your browser as you type.

Can I use it for discounts and tips?+

Yes. Use "X% of Y" for a discount or tip amount, and percentage change to compare prices.

Is it free?+

Yes, completely free — no sign-up and no watermark.

Is my data private?+

Yes — this tool runs entirely in your browser. Your files and text are never uploaded.

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