Percentage Calculator

Calculate percentages, increase, decrease, and difference instantly.

General Calculator

Enter any two values to calculate the third.

of
is

Result

200

20% of 1000 is 200

Common Phrases
What is % of ?
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is what % of ?
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Change from to ?
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Percentage Difference

Find the absolute difference between two values relative to their average.

&

Percentage Difference

40%

The difference is 40% relative to the average of the two values.

Percentage Change

Calculate the increase or decrease from one value to another.

to

Percentage Change

+50%

Increase

What is a Percentage?

A percentage is a way of expressing a number as a fraction of 100. The word “percent” means “per hundred.”

For example: 25% means 25 out of 100

It can also be written as:

  • Fraction: 25/100
  • Decimal: 0.25

Percentages are widely used in daily life for calculations involving discounts, interest rates, profit, marks, and more.

What is a Percentage Calculator?

A percentage calculator is a tool that helps you quickly calculate percentages, including:

  • Finding a percentage of a number
  • Calculating percentage increase or decrease
  • Determining what percentage one number is of another

It saves time and reduces manual errors.

Common Percentage Formulas

1. Percentage of a Number

Percentage = (Value × Percentage) ÷ 100

Example: 20% of 150 = (150 × 20) ÷ 100 = 30

2. Percentage Increase

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

3. Percentage Decrease

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

4. Percentage Difference

Percentage Difference = (Difference ÷ Average) × 100

5. What Percentage One Number is of Another

Percentage = (Part ÷ Whole) × 100

How to Use a Percentage Calculator

Steps:

  1. Choose type of calculation
  2. Enter required values
  3. Click calculate
  4. View the result instantly

Example: Find 30% of 200 → Result: 60

Types of Percentage Calculations

1. Finding a Percentage of a Number

Example: 15% of 80

Solution: (80 × 15) ÷ 100 = 12

2. Finding What Percentage One Number is of Another

Example: 25 is what percent of 200?

Solution: (25 ÷ 200) × 100 = 12.5%

3. Percentage Increase

Example: Original price = 100, New price = 120

Increase: ((120 − 100) ÷ 100) × 100 = 20%

4. Percentage Decrease

Example: Original price = 200, New price = 150

Decrease: ((200 − 150) ÷ 200) × 100 = 25%

Step-by-Step Examples

Example 1: Basic Percentage
Find 10% of 500
Solution: (500 × 10) ÷ 100 = 50

Example 2: Percentage Increase
Price increases from 80 to 100
Solution: ((100 − 80) ÷ 80) × 100 = 25%

Example 3: Percentage Decrease
Price drops from 150 to 120
Solution: ((150 − 120) ÷ 150) × 100 = 20%

Example 4: Finding Percentage
40 is what percent of 160
Solution: (40 ÷ 160) × 100 = 25%

Example 5: Real-Life Example
A student scores 72 out of 90
Percentage: (72 ÷ 90) × 100 = 80%

Percentage Chart (Quick Reference)

PercentageDecimalFraction
10%0.101/10
25%0.251/4
50%0.501/2
75%0.753/4
100%1.001

Percentage Increase/Decrease Chart

Old ValueNew ValueChangePercentage
100120+2020% increase
200150-5025% decrease
80100+2025% increase
5040-1020% decrease

Real-Life Applications of Percentage

  • 1. Shopping Discounts: If an item costs 100 and has a 20% discount, Final price = 80.
  • 2. Exam Results: Marks are often calculated in percentage.
  • 3. Banking & Finance: Interest rates are expressed as percentages.
  • 4. Business Profit & Loss: Used to measure growth or decline.
  • 5. Data Analysis: Used in statistics and comparisons.

Common Mistakes

  • Forgetting to divide by 100
  • Confusing percentage increase with decrease
  • Using wrong base value
  • Incorrect decimal conversion

Tips for Accurate Calculation

  • Always identify the base value
  • Convert percentage to decimal when needed
  • Double-check formulas
  • Use a calculator for complex values

Practice Questions

Find 20% of 250 Ans: 50
50 is what percent of 200? Ans: 25%
Price increases from 300 to 360. Find percentage increase Ans: 20% increase
Price decreases from 500 to 400. Find percentage decrease Ans: 20% decrease
Find 75% of 120 Ans: 90

Why Use a Percentage Calculator?

  • Saves time
  • Eliminates manual errors
  • Handles complex calculations
  • Useful for students and professionals