Percentage Calculator – Calculate Percentages, Increase & Decrease

Percentage Calculator

Use this free Percentage Calculator to calculate percentages, percentage increase, percentage decrease, percentage difference, discounts, and reverse percentages quickly and accurately.

Free Percentage Calculator

Choose a calculation type below and enter your numbers.

%
Result 125
Calculation 25% of 500 = 125
Formula (25 ÷ 100) × 500

Common Percentage Calculations

What Is a Percentage?

A percentage is a number expressed as a fraction of 100. The word percentage comes from the idea of "per hundred." The percentage symbol is %.

For example, 25% means 25 out of 100, or 0.25 as a decimal. Percentages are commonly used for discounts, taxes, interest, grades, statistics, business calculations, price changes, and everyday financial decisions.

How to Use the Percentage Calculator

  1. Select the type of percentage calculation you want to perform.
  2. Enter the required numbers into the calculator.
  3. Click Calculate Percentage.
  4. The calculator will display the result, calculation, and formula used.

Percentage Calculation Types

1. What Is X% of Y?

This calculation finds a percentage of a number.

Result = (Percentage ÷ 100) × Number

Example: 25% of 500 is:

(25 ÷ 100) × 500 = 125

2. X Is What Percent of Y?

Use this calculation when you want to know what percentage one number represents of another number.

Percentage = (X ÷ Y) × 100

Example: 25 is what percent of 100?

(25 ÷ 100) × 100 = 25%

3. Percentage Increase

Percentage increase measures how much a value has increased relative to its original value.

Percentage Increase = ((New Value − Original Value) ÷ Original Value) × 100

Example: A price increases from $100 to $130.

((130 − 100) ÷ 100) × 100 = 30%

4. Percentage Decrease

Percentage decrease measures how much a value has fallen relative to its original value.

Percentage Decrease = ((Original Value − New Value) ÷ Original Value) × 100

Example: A price decreases from $100 to $80.

((100 − 80) ÷ 100) × 100 = 20%

5. Percentage Difference

Percentage difference compares two values without treating either value as the original or starting value.

Percentage Difference = |A − B| ÷ ((A + B) ÷ 2) × 100

Example: Compare 80 and 100.

|80 − 100| ÷ 90 × 100 = 22.22%

Percentage Discount Calculator

Percentages are commonly used to calculate sale prices and discounts. If an item costs $100 and has a 20% discount, the discount amount is:

Discount = Original Price × Discount % ÷ 100
$100 × 20 ÷ 100 = $20 discount

The final price is:

Final Price = Original Price − Discount
$100 − $20 = $80

Reverse Percentage Calculator

Reverse percentage calculations help you find the original value when you know the final value after a percentage increase or decrease.

Finding the Original Value After a Percentage Increase

Original Value = Final Value ÷ (1 + Percentage ÷ 100)

Finding the Original Value After a Percentage Decrease

Original Value = Final Value ÷ (1 − Percentage ÷ 100)

Percentage Examples in Everyday Life

Situation Example Result
Discount 20% off $100 $80
Increase $100 to $120 20% increase
Decrease $100 to $75 25% decrease
Percentage of number 10% of 500 50
Percentage relationship 25 out of 100 25%

Percentage vs Percentage Points

Percentage and percentage points are not always the same thing. A percentage describes a relative change, while percentage points describe the direct difference between two percentage values.

For example, if an interest rate increases from 5% to 6%, the difference is 1 percentage point. The relative increase is:

((6 − 5) ÷ 5) × 100 = 20%

Therefore, the rate increased by 1 percentage point, which represents a 20% relative increase.

Why Use Our Percentage Calculator?

  • Free and easy to use.
  • Works on desktop, tablet, and mobile devices.
  • Calculates several common percentage problems.
  • Shows the calculation and formula used.
  • Useful for discounts, price changes, business, school, finance, and everyday calculations.
  • No complicated mathematical steps are required.

Frequently Asked Questions About Percentages

How do I calculate a percentage?

To calculate a percentage of a number, divide the percentage by 100 and multiply it by the number. For example, 20% of 200 is (20 ÷ 100) × 200 = 40.

What is 25% of 100?

25% of 100 is 25. The calculation is (25 ÷ 100) × 100 = 25.

How do I calculate percentage increase?

Subtract the original value from the new value, divide the result by the original value, and multiply by 100.

How do I calculate percentage decrease?

Subtract the new value from the original value, divide the result by the original value, and multiply by 100.

How do I calculate a discount percentage?

Multiply the original price by the discount percentage and divide by 100. Subtract the discount amount from the original price to find the final price.

What is the difference between percentage and percentage points?

Percentage points represent the direct difference between two percentages. Percentage change measures the relative change from an original value.

Can I use this percentage calculator for discounts?

Yes. Use the Discount Calculator option to estimate the discount amount and final price of an item.

Can I calculate percentage increase and decrease?

Yes. The calculator includes separate options for percentage increase and percentage decrease.

Calculator Information: This percentage calculator is provided for general informational and educational purposes. Always verify important financial, business, tax, or academic calculations when accuracy is critical.

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