Percentage Calculator
Calculate percentages, percentage changes, increases, decreases, and solve percentage problems
Calculation Type
Select the type of percentage calculation you need
Basic Percentage
The part or portion
The total or whole amount
Result
Select calculation type and enter values
Your percentage result will appear here
How It's Calculated
Quick Examples
Basic Percentage
25 is what % of 100?
25%
Percentage Change
From 100 to 120
+20% increase
Percentage Increase
100 + 15%
115
Percentage Decrease
100 - 10%
90
What % Of
50 is what % of 200?
25%
What Is % Of
What is 20% of 150?
30
Understanding Percentages
What Are Percentages?
A percentage is a way of expressing a number as a fraction of 100. The word "percent" means "per hundred" and is represented by the symbol %.
Basic Formula
- Percentage: (Part ÷ Whole) × 100
- Part: (Percentage ÷ 100) × Whole
- Whole: Part ÷ (Percentage ÷ 100)
Percentage Change
- Formula: ((New - Old) ÷ Old) × 100
- Positive result: Percentage increase
- Negative result: Percentage decrease
- Example: From 80 to 100 = 25% increase
Common Uses
- Discounts: 20% off original price
- Tax: 8.5% sales tax
- Tips: 15% gratuity
- Interest: 3.5% annual rate
Types of Calculations
- Basic %: Find what percentage one number is of another
- % Change: Calculate increase or decrease between two values
- % Increase: Add a percentage to a value
- % Decrease: Subtract a percentage from a value
- What % of: Find the percentage relationship
- What is % of: Find the actual value from a percentage
Practical Examples
- Shopping: £80 jacket with 25% discount = £60
- Salary: £50K salary with 5% raise = £52.5K
- Grades: 85 out of 100 questions = 85%
- Growth: Revenue grew from £1M to £1.2M = 20%
Tips & Tricks
- 50%: Half of the number
- 25%: Quarter of the number
- 10%: Move decimal point one place left
- 1%: Move decimal point two places left
- Double check: Percentage + remaining = 100%