Free Percentage Calculator - Calculate Percentages Online

Calculate percentages, percentage changes, increases, decreases, and solve various percentage problems instantly. Our comprehensive percentage calculator handles all types of percentage calculations with step-by-step explanations.

✓ Multiple calculation types ✓ Instant results ✓ Step-by-step explanations ✓ Free to use

Basic Percentage Calculator
Calculate what percentage one number is of another

How to Use Our Percentage Calculator

Our percentage calculator offers four different calculation types to handle all your percentage needs:

Basic Percentage

Find what percentage one number is of another number.

Example: What percentage is 25 of 100? Answer: 25%

Percentage of Number

Calculate what X% of a number equals.

Example: What is 20% of 150? Answer: 30

Percentage Change

Find the percentage increase or decrease between two values.

Example: Change from 100 to 120? Answer: 20% increase

Increase/Decrease

Calculate the final value after applying a percentage change.

Example: 100 increased by 15%? Answer: 115

Percentage Formulas and Calculations

Essential Percentage Formulas

Basic Percentage Formula:

Percentage = (Value ÷ Total) × 100

Use this to find what percentage one number is of another.

Percentage of a Number:

Result = (Percentage ÷ 100) × Number

Use this to calculate X% of any number.

Percentage Change:

Change = ((New - Old) ÷ Old) × 100

Use this to find percentage increase or decrease.

Increase/Decrease:

Final = Original ± (Original × % ÷ 100)

Use this to apply percentage changes to values.

Step-by-Step Calculation Examples

Example 1: Basic Percentage

Question: What percentage is 75 of 300?

Step 1: Divide the value by the total: 75 ÷ 300 = 0.25

Step 2: Multiply by 100: 0.25 × 100 = 25%

Answer: 75 is 25% of 300

Example 2: Percentage Change

Question: What's the percentage change from 80 to 100?

Step 1: Find the difference: 100 - 80 = 20

Step 2: Divide by original value: 20 ÷ 80 = 0.25

Step 3: Multiply by 100: 0.25 × 100 = 25%

Answer: 25% increase

Common Percentage Applications

Business & Finance

  • • Calculate sales tax and discounts
  • • Determine profit margins and markups
  • • Analyze growth rates and returns
  • • Calculate interest rates and fees
  • • Budget allocation and expense tracking

Education & Statistics

  • • Grade calculations and GPA
  • • Test score analysis
  • • Survey results and polling data
  • • Statistical analysis and research
  • • Academic performance tracking

Health & Fitness

  • • Body fat percentage calculations
  • • Weight loss/gain tracking
  • • Nutritional value analysis
  • • Exercise progress monitoring
  • • Medical test result interpretation

Daily Life

  • • Shopping discounts and sales
  • • Tip calculations at restaurants
  • • Utility bill changes
  • • Recipe scaling and cooking
  • • Home improvement projects

Percentage Calculator Tips

Quick Mental Math Tricks

10%: Move decimal point one place left

1%: Move decimal point two places left

50%: Divide by 2

25%: Divide by 4

20%: Divide by 5

5%: Half of 10%

15%: 10% + 5%

30%: 3 × 10%

Common Mistakes to Avoid

  • • Don't confuse percentage points with percentages
  • • Remember that percentage change is relative to the original value
  • • Be careful with negative numbers in percentage calculations
  • • Always double-check your decimal placement