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Percentage Calculator

Five calculators for all your percentage needs. Enter your values and get instant results.

Calculate a percentage of a number

What is X% of Y?

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Percentage means "per hundred". 20% of 150 is like dividing 150 into 100 parts and taking 20. Shortcut: divide by 100, multiply by the percentage. 150 ÷ 100 = 1.5 → 1.5 × 20 = 30.

Find what percentage a number represents

What percentage is X of Y?

Ask yourself: 15 is how many parts out of 60? Divide the smaller by the larger, multiply by 100. 15 ÷ 60 = 0.25 → × 100 = 25%. Tip: if the result exceeds 100%, it means the first number is larger than the second.

Calculate percentage change

What is the change between two values?

The change measures how much it moved from the starting point. Formula: (new − old) ÷ old × 100. If positive it increases, negative it decreases. Tip: think of your old price as the reference, it's always the basis.

Add a percentage to a number

What is Y increased by X%?

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Adding 20% means multiplying by 1.20. The "1" is the starting number, the "0.20" is the percentage. Tip: for 20% VAT, always multiply by 1.20. 5.5% VAT? Multiply by 1.055.

Subtract a percentage from a number

What is Y decreased by X%?

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Subtracting 30% means keeping 70%. Multiply by 0.70. Sale tip: −30% → × 0.70, −50% → × 0.50. Calculate in your head at the store: an item at 80 € with −25% is 80 × 0.75 = 60 €.
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Calculate a Percentage of a Number

What is X% of Y?

Calculate a Percentage Increase

What is Y increased by X%?

Calculate a Percentage Decrease

What is Y decreased by X%?

Calculate Percentage Change

What is the change between two values?

How to calculate percentages easily

A percentage is a proportion expressed per hundred. It's one of the most common mathematical operations in daily life: calculating a discount during sales, understanding a salary increase, determining a VAT rate, or converting a grade out of 20 to a percentage.

The five calculators on this page cover the most common use cases. "X% of Y" applies a rate to a value. "What percentage is X of Y" finds the ratio between two numbers. "Change" measures the evolution between an old and a new value. "Add" and "Subtract" apply a percentage increase or decrease to a starting amount.

The underlying formulas are simple. To find X% of Y: multiply Y by X/100. To determine what percentage X is of Y: divide X by Y then multiply by 100. For change: (new value − old value) / |old value| × 100. To add X% to Y: Y × (1 + X/100). To subtract: Y × (1 − X/100).

This tool calculates results instantly as you type, with no sign-up or server request required. It accepts both comma and period as decimal separator. All calculations are performed locally in your browser.

Frequently asked questions

Multiply the number by 0.20 (or divide it by 5). For example, 20% of 150 = 150 × 0.20 = 30. You can also use our first calculator: enter 20 in the percentage field and 150 in the number field.
Divide the partial value by the total value, then multiply by 100. For example, 15 out of 60: (15 / 60) × 100 = 25%. Use our "Between two numbers" calculator to get the result instantly.
Apply the formula: (new value − old value) / |old value| × 100. A positive result indicates an increase, a negative result a decrease. For example, from 80 to 100: (100 − 80) / 80 × 100 = +25%.
To add 20% VAT (standard rate in France), multiply the price excluding tax by 1.20. For example, 100 € excluding tax × 1.20 = 120 € including tax. Use our "Add a percentage" calculator by entering 20 and the amount excluding tax.
No. All calculations are performed directly in your browser using JavaScript. No data is transmitted to our servers. You can even use this tool offline once the page is loaded.