Percentage Calculator

Find percentages quickly for everyday math, schoolwork, shopping, grades, discounts, tips, markups, and percentage changes. The tool lets you calculate a percentage of a number, find what percent one value is of another, measure changes between two values, and increase or decrease a number by a chosen rate.

Enter your values in the appropriate fields and the result appears automatically. You can also view the formula and calculation steps to understand how the answer was found.

What Can You Calculate?

Different percentage problems require slightly different calculations. This tool supports the most common types in one place.

You can use it to:

• Find a percentage of any number
• Determine what percent one number is of another
• Calculate percentage increase or decrease
• Increase a value by a certain percent
• Reduce a value by a certain percent
• Work out discounts and sale prices
• Calculate tips and markups
• Convert scores into percentages

Choose the calculation that matches your question, enter the required numbers, and review the result.

How to Use the Tool

For a question such as “What is 15% of 200?”, enter 15 as the percentage and 200 as the number.

If you want to know what percent one value is of another, enter the smaller or measured amount as the part and the total amount as the whole.

For percentage change, enter the starting value and ending value. The tool compares them and shows whether the value increased or decreased.

To add or subtract a percent from a number, enter the original value, choose increase or decrease, and enter the percentage.

The page also provides quick percentage options and example calculations that can help you see how each mode works.

Understanding Your Result

A percentage expresses a value in relation to 100.

For example, 25% means 25 out of every 100. It can also be written as the decimal 0.25 or the fraction 25/100, which simplifies to 1/4.

If 20 students out of a class of 25 pass an exam, the passing percentage is:

20 ÷ 25 × 100 = 80%

This means 80 out of every 100 students would represent the same proportion.

The meaning of your answer depends on the calculation. A result may represent part of a total, a grade, a discount amount, a price increase, or a change between two values.

How Percentage Calculations Work

There are several common formulas, depending on what you are trying to find.

To find a percentage of a number:

Percentage ÷ 100 × Number

Example:

15 ÷ 100 × 200 = 30

So, 15% of 200 is 30.

To find what percent one number is of another:

Part ÷ Whole × 100

Example:

45 ÷ 60 × 100 = 75%

So, 45 is 75% of 60.

To find percentage change:

(New Value − Original Value) ÷ Original Value × 100

A positive answer represents an increase. A negative answer represents a decrease.

Percentage Increase

Percentage increase shows how much a value has grown compared with where it started.

Suppose a value rises from 80 to 100.

First find the difference:

100 − 80 = 20

Then divide the difference by the original value:

20 ÷ 80 = 0.25

Multiply by 100:

0.25 × 100 = 25%

The value increased by 25%.

The original value is important because percentage change is measured relative to the starting amount.

Percentage Decrease

Percentage decrease measures how much a value has fallen compared with its original amount.

Suppose a price drops from $100 to $75.

The difference is:

100 − 75 = 25

Divide the decrease by the original value:

25 ÷ 100 = 0.25

Then multiply by 100:

0.25 × 100 = 25%

The price decreased by 25%.

Increasing a Number by a Percent

Sometimes you need the new total after adding a percentage rather than only finding the percentage amount.

For example, increase 200 by 15%.

First calculate 15% of 200:

200 × 0.15 = 30

Then add the increase:

200 + 30 = 230

The new value is 230.

This type of calculation can be useful for price increases, markups, growth rates, fees, or other adjustments.

Decreasing a Number by a Percent

To reduce a number, calculate the percentage amount and subtract it from the original value.

For example, reduce 200 by 15%.

15% of 200 is 30.

Then:

200 − 30 = 170

The reduced value is 170.

This method is commonly used for discounts, price reductions, and decreases in measured values.

Calculating Discounts and Sale Prices

Percentages are often used when shopping.

Suppose an item costs $80 and has a 20% discount.

First calculate the discount:

80 × 0.20 = 16

Then subtract it from the original price:

80 − 16 = 64

The sale price is $64.

Remember that the discount amount and the final price are different values. A 20% discount in this example is $16, while $64 is the amount you actually pay.

Finding a Test or Assignment Percentage

A score can be converted into a percentage by dividing the points earned by the total possible points.

For example, if you score 42 out of 50:

42 ÷ 50 × 100 = 84%

Your score is 84%.

The same method works for quizzes, assignments, exams, and other point-based assessments.

Calculating Tips

To calculate a tip, find the required percentage of the bill.

For a $50 bill with a 15% tip:

50 × 0.15 = 7.50

The tip is $7.50.

If you also want the total amount to pay:

50 + 7.50 = 57.50

The total is $57.50.

Percentages, Decimals, and Fractions

Percentages can often be converted into decimals by dividing by 100.

For example:

• 50% = 0.50
• 25% = 0.25
• 10% = 0.10
• 5% = 0.05
• 1% = 0.01

To convert a decimal into a percent, multiply it by 100.

For example:

0.75 × 100 = 75%

Fractions can also be expressed as percentages by dividing the numerator by the denominator and multiplying by 100.

For example:

3 ÷ 4 × 100 = 75%

So, 3/4 equals 75%.

Percentage Change vs Percentage Difference

Percentage change compares a new value with an original value. It is useful when there is a clear starting point, such as a price moving from $50 to $60.

Percentage difference is used when comparing two values without treating either one as the original value. Because these calculations answer different questions, they should not be treated as interchangeable.

For increases and decreases over time, percentage change is usually the appropriate calculation.

Percentage vs Percentage Points

Percent and percentage points do not mean the same thing.

Suppose a rate rises from 20% to 25%.

The increase is 5 percentage points because:

25% − 20% = 5 percentage points

However, the relative percentage increase is:

(25 − 20) ÷ 20 × 100 = 25%

Being clear about this difference is useful when comparing grades, survey results, rates, statistics, and other values already expressed as percentages.

Common Percentage Examples

Here are a few simple examples:

10% of 500

500 × 0.10 = 50

25% of 80

80 × 0.25 = 20

50 is what percent of 200?

50 ÷ 200 × 100 = 25%

Increase 120 by 10%

120 + 12 = 132

Decrease 120 by 10%

120 − 12 = 108

The same formulas work with whole numbers and decimal values.

Frequently Asked Questions

How do I find a percentage of a number?

Divide the percentage by 100 and multiply the result by the number. For example, 20% of 80 is calculated as 0.20 × 80, which equals 16.

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

Divide the part by the whole and multiply by 100. If the values are 30 and 120, the calculation is 30 ÷ 120 × 100 = 25%.

How do I calculate a percentage increase?

Subtract the original value from the new value. Divide that difference by the original value, then multiply by 100.

How do I calculate a percentage decrease?

Subtract the new value from the original value. Divide the decrease by the original amount and multiply by 100.

How do I add 20% to a number?

Multiply the original number by 0.20 to find the increase, then add that amount to the original number. You can also multiply the original number directly by 1.20.

How do I subtract 20% from a number?

Multiply the number by 0.20 to find the amount being removed, then subtract it. Another method is to multiply the original value by 0.80.

How do I calculate a discount percentage?

Multiply the original price by the discount rate written as a decimal. Subtract that amount from the original price to find the final sale price.

How do I convert a score into a percent?

Divide the points earned by the total possible points and multiply by 100. A score of 36 out of 40, for example, equals 90%.

Can a percentage be greater than 100%?

Yes. A percentage can exceed 100 when a value is greater than the reference amount. For example, 150 is 150% of 100.

Can a percentage be negative?

Yes. Negative percentages may appear when describing decreases, losses, or values below a reference point. In percentage-change calculations, a negative result usually indicates a decrease.

What is 1% of a number?

Divide the number by 100. For example, 1% of 500 is 5.

What is the easiest way to find 10%?

Divide the number by 10. For example, 10% of 240 is 24.

Why is the original number important in percentage change?

Percentage change measures the difference relative to the starting value. Using a different reference value can produce a different percentage, even when the numerical difference stays the same.