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

Divide the first number by the second, then multiply by 100. Formula: (X ÷ Y) × 100. For example, if you scored 45 out of 60 on a test, your percentage is (45 ÷ 60) × 100 = 75%. Use our "X is what % of Y?" mode for this.

How do I add or subtract a percentage from a number?

To add X% to Y, calculate X% of Y and add it: Y + (X ÷ 100) × Y. Equivalently, multiply Y by (1 + X÷100). To subtract, use Y − (X ÷ 100) × Y, or multiply by (1 − X÷100). Our "Add %" and "Subtract %" modes do both instantly.

Is my calculation data stored or shared?

No. All calculations happen entirely in your browser using JavaScript. Your numbers are never sent to a server, logged, or shared. This is completely private — even if you disconnect from the internet, the calculator continues to work.

Can I use decimals and negative numbers?

Yes. Our calculator accepts any real number, including decimals (like 12.5%) and negative values (useful for tracking losses or decreases). The step-by-step explanation will show you how negative values are handled in the formula.

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Percentage Calculator

Q: What is a percentage?

A percentage is a way of expressing a number as a fraction of 100. The word comes from the Latin "per centum" meaning "by the hundred." For example, 25% means 25 out of every 100, or 0.25 in decimal form. Percentages are used everywhere — discounts, interest rates, test scores, statistics, and more.

Q: How do I calculate X% of a number?

To find X% of a number Y, multiply Y by X and divide by 100. The formula is: (X ÷ 100) × Y. For example, 15% of 200 = (15 ÷ 100) × 200 = 0.15 × 200 = 30. Our "What is X% of Y?" mode does this calculation automatically.

Q: How do I calculate percentage increase or decrease?

Subtract the old value from the new value, divide by the old value, then multiply by 100. Formula: ((New − Old) ÷ |Old|) × 100. A positive result is an increase; a negative result is a decrease. For example, going from 80 to 100 is ((100 − 80) ÷ 80) × 100 = 25% increase.

Q: What is the difference between percentage and percentage points?

Percentage points measure absolute change, while percentage measures relative change. If interest rates go from 4% to 6%, that is a 2 percentage point increase — but a 50% relative increase. Confusing the two is a common error in news reporting, especially in finance and statistics.

Calculate percentages easily — find percent of a number, percent change, and more.

What is % of ?

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From to — percent change?

Add % to

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About Our Percentage Calculator

Percentages are used in everyday life such as discounts, interest on loans, tips at restaurants, exam scores, tax, pay rises, body fat percentage, battery life and polling stats. However when doing manual calculations, they can be very easy to make mistakes. For example adding an extra zero or decimal can turn a 15% discount into a 150% increase.

Our percentage calculator helps you with the top 5 percentage questions you have. It also gives you a detailed breakdown of how it got to the answer. Whether you're a student, or just want quick maths done, this will give you the correct answer in seconds. Everything is done inside your browser.

Using The Percentage Calculator

This calculator includes the top 5 percentage questions:

What is X% of Y? And that will give you the percentage of a number. For instance, What is 15% of 200? This will give you 30. This is the most commonly used percentage question.
X is what % of Y? This gives you the percentage of one number against another. For example, 45 is what % of 60? This will give you 75%. This is useful for exam scores.
Percentage Increase/Decrease This will give the percent increase or decrease in any number. For example, 80 to 100 is a 25% increase. This can be used to calculate growth or loss in any number.
Increase by % This increases a number by a certain percentage. For example, increase 20% of 500 = 600. This is perfect for finding the final price after tax.
Decrease by % This decreases a number by a certain percentage. For example, decrease 25% of 400 = 300. This is useful for finding discounts.

How to Use

Select which percentage you need to calculate by clicking on one of the tabs above.
Add in the numbers into the input boxes. Each box has been clearly marked with what it represents (X%, Y).
Click calculate and instantly get your answer. The formula is also shown.
View the detailed breakdown of the calculation to understand how it was calculated.

Why Use Our Calculator?

There are many percentage calculators online however ours has several benefits:

5 in One. All 5 of the most common percentage questions are included in one place.
Detailed Breakdown. All answers have a detailed breakdown so you can check the calculations.
Clear Formula. The formula is shown clearly below the answer.
Privacy. No calculations are sent to the server. All calculations are done inside your browser.
Use Decimals. This calculator can handle decimals and negative numbers.

Common Uses For Percentages

Percentages are widely used in everyday life. They are commonly used for:

Discounts whilst shopping (eg 30% off a ₹2000 item)
Adding or subtracting tax or VAT from an amount
Finding the tip amount at restaurants
Exam scores (eg 45 out of 60 = 75%)
Tracking pay increases or raises (eg 8% increase)
Interest rates on loans and credit cards
Inflation
Tracking business growth or loss
Understanding statistics and polling
Body Fat percentage or tracking fitness

Percentage Formulas

If you ever need to do manual calculations here are the formulas:

X% of Y = (X ÷ 100) x Y
X is what % of Y = (X ÷ Y) x 100
Percentage Increase/Decrease from A to B = ((B - A) ÷ |A|) x 100
Increase by X% = Y x (1 + (X ÷ 100))
Decrease by X% = Y x (1 - (X ÷ 100))

These formulas are easy to get wrong. Especially if dealing with negative numbers, or if you're unsure what the original number is. Our calculator takes away all of the guess work.

FAQs

What is a percentage?

Percent means the expression of a value as the ratio of the value to 100. The term percent comes from Latin per centum meaning "for each 100". Therefore, 25% means 25 for each 100 or 0.25 in decimal notation._percentages are applied to everything from discounts and interest rates to test scores and statistics.

How do I calculate X% of a number?

To find a percentage of a number we multiply the number by the percentage. This can be shown by the formula: (X ÷ 100) x Y. For example 15% of 200 = (15 ÷ 100) x 200 = 0.15 × 200 = 30%. Our What is X% of Y? function does this automatically.

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

The formula for determining the percentage of one number to another number is to divide the two numbers and multiply by 100. It is shown as (X ÷ Y) x 100. Suppose if you scored 45 marks out of 60 in a test then the percentage will be (45 ÷ 60) x 100 which is 75%.

How do I calculate percentage increase or decrease?

To find out the percentage increase or decrease between two numbers simply take away the old value from the new value, divide by the old value and multiply by 100. The formula is ((New - Old) ÷ |Old|) x 100. If the answer is positive it is an increase, if it's negative it is a decrease. For example, 80 to 100 is ((100 - 80) ÷ 80) x 100 = 25% increase.

Whats the difference between percentage and percentage points?

Percentage points are different to percentage. Percentage points are used to describe the actual change between numbers. Whereas percentage is used to describe the relative change. For example, an increase from 4% to 6% interest rate is 2 percentage points, but it is a 50% increase. This is a common mistake in the media, especially when dealing with financial or statistical information.

How do I increase or decrease by a percentage?

To increase by X% simply calculate X% of the number and add it to the original number. Or simply multiply by (1 + (X ÷ 100)). To decrease by X% simply do Y - (X ÷ 100) x Y. Or multiply by (1 - (X ÷ 100)). Our Add % and Subtract % functions do this instantly.

Are my calculations saved or shared?

No. All calculations are done within your browser using JavaScript. No calculations are sent to the server, stored or shared. Everything is fully private. In case you lose your Internet connectivity, the online calculator will continue functioning.

Can I use decimals?

Yes. You can use any real number. This includes decimals (eg 12.5%). You can also use negative numbers (useful for tracking loss). The detailed breakdown shows how negative numbers are handled.

Other Tools You May Find Useful

If you found this percentage calculator useful you may also want to try our tip calculator, loan calculator or BMI calculator.