Free Percentage Calculator Online

Use our free percentage calculator to get instant, accurate results — no signup, no hassle. Whether you’re calculating discounts, grades, or price changes, it’s fast, simple, and works right in your browser.

Quick Features

What is a Percentage Calculator?

A percentage calculator is a simple online tool that helps you work with percentages quickly and accurately.

You don’t need to remember any formulas. Just enter your numbers, choose what you want to find, and get your answer instantly.

People use a percentage calculator in all kinds of situations:

• Shopping — find the sale price after a discount or check how much you’re saving
• Finance — calculate interest, profit margins, or investment returns
• Education — figure out exam scores, grade percentages, or test results

Whether you need to find a percentage of a number, calculate a percentage increase or decrease, or figure out the original price before a discount, this tool handles it all.

It saves time, reduces errors, and works for students, shoppers, and professionals alike. No math degree required.

Percentage Formulas & Examples

1. X% of Y (Find a Percentage of a Number)

Formula:

Result = (X / 100) x Y

Use this when you want to find what a percentage of a number actually equals.

Example: What is 20% of 150?

(20 / 100) x 150 = 30

Answer: 30

2. X is What % of Y?

Formula:

Percentage = (X / Y) x 100

Use this to find out what percentage one number is of another.

Example: 45 is what % of 180?

(45 / 180) x 100 = 25%

Answer: 25%

3. Percentage Increase / Decrease

Formula:

% Change = ((New Value – Old Value) / Old Value) x 100

Use the percentage change formula to track how much something has gone up or down.

Example: Price went from $80 to $100. What is the percentage increase?

((100 – 80) / 80) x 100 = 25%

Answer: 25% increase

4. Add a Percentage to a Number

Formula:

Result = Y + (X / 100) x Y

Use this to add a percentage on top of a value — like adding tax or a tip.

Example: Add 15% to $200.

200 + (15 / 100) x 200 = 200 + 30 = $230

Answer: $230

5. Subtract a Percentage from a Number

Formula:

Result = Y – (X / 100) x Y

Use this to remove a percentage from a value — like applying a discount.

Example: Subtract 10% from $500.

500 – (10 / 100) x 500 = 500 – 50 = $450

Answer: $450

6. Find the Original Value (Before % Change)

Formula:

Original Value = Current Value / (1 + (X / 100))

Use this to work backwards — find what the price was before a percentage was added.

Example: A price is $120 after a 20% increase. What was the original price?

120 / (1 + (20 / 100)) = 120 / 1.2 = $100 Answer: $100

How to Use the Percentage Calculator

1. Select your calculation type — choose from options like ‘X% of Y’, ‘percentage increase’, or ‘find original value’.
2. Enter your numbers — type in the values you want to calculate. No commas or symbols needed.
3. Click Calculate — the tool instantly applies the correct percentage formula and shows your result.
4. View your result — see the answer clearly displayed, ready to use or copy.

Why Use a Percentage Calculator?

• Saves time — get your answer in seconds instead of doing the math by hand.
• Always accurate — no rounding errors, no manual mistakes, just reliable results every time.
• Covers every use case — from discount percentage calculations to grade scores and investment returns.
• No signup needed — open the tool and start calculating right away, completely free.
• Works on any device — use it on your phone, tablet, or desktop without installing anything.
• Beginner-friendly — no math knowledge required; just enter numbers and get results.
• Great for daily tasks — shopping, splitting bills, checking grades, or tracking prices made easy.

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Frequently Asked Questions

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