Percentage Calculator (Free, Fast & Accurate)

What is a Percentage Calculator?

A percentage calculator is a tool that helps you quickly work out percentage-based problems that come up in everyday life — from calculating a restaurant tip to understanding a salary increase or figuring out a sale discount. Instead of doing the math by hand, you get an instant, accurate answer.

Our calculator offers four distinct modes so you can solve any percentage problem, no matter which direction you're working from.

How It Works

Simply select the calculation mode that matches your question, enter your numbers, and hit Calculate. The result appears instantly. Use the Copy button to grab the answer for use elsewhere.

Real-World Examples

Sales discount: A $250 jacket is 30% off — that's $75 off, so you pay $175. Use "% of Number" mode.
Exam score: You got 42 out of 60 questions right. That's 70%. Use "X is what %" mode.
Salary raise: Your salary went from $50,000 to $55,000. That's a 10% increase. Use "% Change" mode.
Tax calculation: After 15% tax you paid $23. The pre-tax price was $20. Use "Find Original" mode.
Investment return: Your stock went from $120 to $96. That's a −20% drop. Use "% Change" mode.

The 4 Calculation Modes

% of Number — Finds a percentage of any value. Perfect for discounts, tips, and commission calculations.

X is what % of Y — Finds what percentage one number is of another. Great for test scores and ratios.

% Change — Calculates how much something increased or decreased as a percentage. Useful for prices, revenue, and growth rates.

Find Original — Works backwards from a result and a percentage to find the starting value. Handy for reverse-engineering taxes or discounts.

Frequently Asked Questions

How do I calculate a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 20% of 150 = 150 × 20 ÷ 100 = 30. Our "% of Number" mode does this instantly.

How do I calculate percentage change?

Percentage change = ((New Value − Old Value) ÷ Old Value) × 100. A positive result is an increase; negative is a decrease. For example, going from 80 to 100 is a 25% increase.

What is the formula for percentage?

The core formula is: Percentage = (Part ÷ Whole) × 100. This tells you what fraction of a whole a specific part represents, expressed as a number out of 100.

How do I find the original price before a percentage increase?

Divide the final value by (1 + percentage/100). Or use our "Find Original" mode — enter the final value and the percentage, and we'll calculate the starting value automatically.

Is this calculator free to use?

Yes — completely free, with no signup, no account, and no limits. Use it as many times as you need.