Percentage Calculator

Calculate percentages with four modes: X% of Y, what percent X is of Y, percentage change, and percentage difference.

percentPercentage Calculator

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Calculation Mode

Select Mode

Percentage

Number

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Results

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Enter values to see results

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About Percentage Calculator

The Percentage Calculator is a versatile tool that handles all common percentage operations in one place. Whether you need to find what a specific percentage of a number is, determine what percent one number is of another, calculate the percentage change between two values, or find the percentage difference, this calculator covers it all with instant real-time results.

All calculations run entirely in your browser with no data sent to any server. Simply select your calculation mode, enter two values, and see the answer immediately along with a detailed formula breakdown. It is perfect for students, professionals, shoppers comparing prices, or anyone working with percentages in daily life.

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How to Use

Choose a Calculation Mode

Select one of four modes: "X% of Y" to find a percentage of a number, "X is what % of Y" to find what percent a value represents, "% Change" for increase or decrease between values, or "% Difference" for the relative difference between two numbers.

Enter the First Value

Type the first number into the input field. Depending on the mode, this will be the percentage, the value, or the starting number.

Enter the Second Value

Type the second number. This is the base number, total, ending value, or comparison value depending on the selected mode.

View Your Results

Results appear instantly as you type. See the main result highlighted in a card, along with a detailed calculation breakdown showing the formula used. In "X% of Y" mode, a quick reference table also shows common percentages.

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Frequently Asked Questions

How do I calculate a percentage of a number? expand_more

Select the "X% of Y" mode, enter the percentage in the first field and the number in the second field. The calculator multiplies the number by the percentage divided by 100. For example, 15% of 200 equals 200 × (15/100) = 30.

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

Use the "X is what % of Y" mode. Enter the part value in the first field and the total in the second. The calculator divides the part by the total and multiplies by 100. For example, 30 is (30 ÷ 200) × 100 = 15% of 200.

What is the difference between percentage change and percentage difference? expand_more

Percentage change measures the relative change from an original value to a new value and has a direction (increase or decrease). Percentage difference measures the relative difference between any two values without implying a direction — it is always positive and uses the average of the two values as the denominator.

Can the percentage change be negative? expand_more

Yes. When the new value is smaller than the original, the percentage change is negative, indicating a decrease. The calculator highlights decreases in red and increases in green so you can see the direction at a glance.

Is my data secure when using this calculator? expand_more

Yes. All calculations happen locally in your browser using JavaScript. No numbers or results are sent to any server. The tool works fully offline once loaded.