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Percentage Calculator

Q: What does X% of Y mean?

Multiplying Y by X/100. For example, 25% of 200 = 50.

Q: How is percentage change calculated?

((new - original) / original) × 100%. Positive = increase, negative = decrease.

Q: Can I calculate sales tax with this?

Yes. Use '% of a Number' mode with tax rate as X and purchase amount as Y.

Q: Is my data stored or sent anywhere?

No. All calculations happen in your browser.

Three calculation modes: find what percent X is of Y, calculate percentage change, or apply a percentage to a number.

Calculate X% of Y

Percentage (%)

Number (Y)

About This Percentage Calculator

This free online percentage calculator handles all common percentage operations. Use it for sales and discounts ("What's the final price after 25% off?"), tip calculation, grade calculation, investment returns, and tax calculations. All three modes are available with instant results.

Common Uses

Sales & Discounts — "What's the final price after 25% off?"
Tip Calculation — "What's 18% tip on a $47 bill?"
Grade Calculation — "I got 38 out of 50 — what percentage is that?"
Investment Returns — "My portfolio grew from $5,000 to $5,800 — what percentage increase?"
Tax Calculation — "8% sales tax on a $120 purchase"

How to Use

Select your calculation mode using the tabs above
Enter your values into the input fields
Click Calculate to see the result instantly

Frequently Asked Questions

What does "X% of Y" mean?

It means multiplying Y by X/100. For example, 25% of 200 = 200 × 0.25 = 50.

How is percentage change calculated?

Percentage change = ((new - original) / original) × 100%. A positive result means an increase, negative means a decrease.

Can I calculate sales tax with this?

Yes. Use the "% of a Number" mode: enter the tax rate as X and the purchase amount as Y.

Is my data stored or sent anywhere?

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