Percentage Calculator - Free Online Tool

Q: How do I calculate my exam percentage?

Use the Grade / Marks % tab. Enter the marks you obtained and the total marks possible, then click Calculate. The formula used is (Obtained / Total) x 100. For example, 425 out of 500 gives 85%.

Q: How do I calculate a discount price?

Switch to the Discount / Sale tab, enter the original price and the discount percentage (0-100). The tool shows the final price you pay and the amount you save. For example, 25% off 1000 gives a final price of 750 with 250 saved.

Q: What does X is what percent of Y mean?

This mode answers what percentage does X represent out of Y. For example, 50 is what % of 200 gives 25%. It is useful for finding attendance rates, completion rates or share of a total.

Calculate percentages instantly for school and college grades, shopping discounts, salary increases, price decreases, and more. This free online percentage calculator runs entirely in your browser with no signup, no ads on the tool, and no data collection.

Quick Answer: A percentage calculator converts numbers into percentage values using the formula (Part / Total) x 100. Use it to find grades, discounts, tips, tax, percentage change, or "what % of X is Y" - all in one tool.

Result

How to Use the Percentage Calculator

1Choose the calculation type from the tabs (Grade, % of Number, Discount, etc.).
2Enter your numbers in the input boxes - each field shows a hint of what to type.
3Click the blue "Calculate" button, or press Enter on your keyboard.
4Read the result along with the formula explanation shown below it.
5Click "Copy" to copy the result, or "Reset" to clear the fields and start again.

Features

6 Calculation Modes

Grade, % of number, % change, discount and more - all in one place.
Instant Results

Live calculations as you type - no waiting, no page reloads.
100% Private

Everything runs in your browser. No numbers are sent to any server.
Mobile Friendly

Fully responsive design works on phones, tablets and desktop.
One-Click Copy

Copy any result to your clipboard with a single click.
Formula Shown

Each result displays the formula and steps so you learn how it works.

Which Mode Should You Use?

Mode	Use It For	Example
Grade / Marks %	School or college exam percentages	Scored 425 of 500 = 85%
% of a Number	Finding a portion of a value	20% of 500 = 100
X is what % of Y	Comparing a value to a total	50 is 25% of 200
% Increase	Salary raises, growth, price hikes	100 to 150 = 50% up
% Decrease	Weight loss, price drops	200 to 150 = 25% down
Discount / Sale	Shopping deals and final price	1000 - 25% = 750

Common Mistakes & Tips

Do not confuse "% of" with "% change" - they use different formulas.
For grade calculations, always enter Obtained Marks first, then Total Marks.
Discount percentage must be between 0 and 100 - anything else is invalid.
Total or Old value cannot be zero - division by zero is mathematically undefined.
Decimal numbers are supported (e.g. 87.5) - use a dot, not a comma.

Frequently Asked Questions

How do I calculate my exam percentage?

Use the "Grade / Marks %" tab. Enter the marks you obtained and the total marks possible, then click Calculate. The formula used is (Obtained / Total) x 100. For example, 425 out of 500 gives 85%.

How do I calculate a discount price?

Switch to the "Discount / Sale" tab, enter the original price and the discount percentage (0-100). The tool shows the final price you pay and the amount you save. For example, 25% off 1000 gives a final price of 750 with 250 saved.

What is the formula for percentage increase or decrease?

Percentage change = ((New Value - Old Value) / Old Value) x 100. A positive result is an increase; a negative result is a decrease. The tool handles both automatically and labels the result clearly.

Can I calculate the percentage of a decimal number?

Yes. All input fields accept decimal values. For example, you can find 12.5% of 87.4 without any issue. Just use a dot as the decimal separator, not a comma.

Is this percentage calculator free to use?

Yes, this tool is 100% free with no signup, no login and no usage limit. You can use it as many times as you want on any device with a browser.

Are my numbers saved or sent anywhere?

No. This calculator is fully client-side - meaning every calculation happens inside your own browser. Nothing is uploaded, tracked or stored on any server.

Does this work on mobile phones?

Yes, the interface is fully responsive and touch-friendly. It works smoothly on Android, iPhone, iPad, tablets and desktop browsers alike.

What does "X is what percent of Y" mean?

This mode answers "what percentage does X represent out of Y?". For example, "50 is what % of 200" gives 25%. It is useful for finding attendance rates, completion rates or share of a total.

Related Tools

Explore More Free Tools

Discover the complete UD Tools library - calculators, generators, converters and more.

Explore All Tools

Developed By

Muhammad Usman

Founder, Developer & CEO

Building free, fast, and practical web tools for everyday users — from image converters to text utilities, designed to solve real problems without ads getting in your way.

Our Tools & Applications

📝

NoteVaultPro App