How do I find 20% of a number?

Use the '% of a Number' tab. Enter 20 in the percentage field and your number in the second field. Click Calculate for the instant answer.

How do I calculate percentage change?

Use the '% Change' tab. Enter the old value and new value. The calculator shows the exact percentage increase or decrease.

How do I add tax or discount to a price?

Use the 'Add / Subtract %' tab. Enter the original price, choose Add or Subtract, then enter the percentage. You'll get the final amount instantly.

Is this calculator free?

Yes, completely free. No signup, no download, no limits.

Percentage Calculator – Free Online Percent Calculator

Percentages in Everyday Life

Percentages show up everywhere — a 10% restaurant tip, a 30% off sale, your exam score, a salary raise negotiation, tax on a purchase. The math isn't hard, but doing it mentally is annoying. This calculator handles all four common situations.

Common mistake: A $120 item with 20% off — most people subtract 20 from 120 and get $100. Wrong. The answer is $96. Use the Add / Subtract % tab to get it right, every time.

About the Percentage Calculator

A percentage calculator handles the everyday percentage math people constantly need — what's 20% of 350, what percentage is 45 out of 60, or what number is 15% of a total. It covers the three most common percentage questions in one tool instead of you trying to remember which way to divide or multiply.

Why This Tool Exists

Percentage math seems simple until you're trying to remember whether to multiply by 100 or divide, especially under pressure like calculating a discount or figuring out a test score. This tool exists to remove that guesswork entirely — just pick the type of calculation and enter your numbers.

How to Use It

Step 1. Choose the type of percentage calculation you need (X% of Y, X is what % of Y, or percentage increase/decrease).
Step 2. Enter your numbers into the relevant fields.
Step 3. Click Calculate.
Step 4. Get your answer instantly, with the formula shown for reference.

Key Features & Benefits

Covers multiple percentage calculation types in one place
Shows the formula used, not just the raw answer
Handles decimals and large numbers without issue
Useful for school, shopping, finance, and everyday math
Instant results with no page reload
Simple enough for quick use on mobile

How It Works

The core formula for 'X% of Y' is (X ÷ 100) × Y — so 20% of 350 is (20÷100) × 350 = 70. For 'what percentage is A of B,' the formula flips to (A ÷ B) × 100 — so 45 out of 60 works out to 75%. The calculator runs whichever version you need instantly, without you having to remember which formula applies to which question.

Frequently Asked Questions

How do I calculate a percentage of a number?

Divide the percentage by 100, then multiply by the number. For example, 20% of 350 is (20/100) × 350 = 70.

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

Divide the part by the whole, then multiply by 100. For example, 45 out of 60 is (45/60) × 100 = 75%.

How is percentage increase calculated?

Subtract the old value from the new value, divide by the old value, then multiply by 100 to get the percentage increase.

Can this calculator handle negative percentages?

Yes, it can show percentage decreases as negative values when the new number is lower than the original.

Is this the same as the percentage change calculator?

This tool covers general percentage math; our dedicated percentage change calculator focuses specifically on increase/decrease between two values with more detail.

Percentage Calculator