Percentage Calculator
Calculate percentages and convert between different formats
Percentage Calculator
Table of Contents
Understanding Percentages
A percentage represents a part of a whole, expressed as a number out of 100. The term comes from the Latin "per centum," meaning "by the hundred."
Key Concepts:
- 100% represents the whole amount
- 50% is half of the total
- 25% is one-quarter of the total
- Percentages can be expressed as decimals (75% = 0.75) or fractions (75% = 3/4)
How to Calculate Percentages
To calculate a percentage of a number:
Result = (Percentage ÷ 100) × Value
For example, to calculate 15% of 200:
- Convert percentage to decimal: 15 ÷ 100 = 0.15
- Multiply by the value: 0.15 × 200 = 30
- Therefore, 15% of 200 is 30
Common Uses
Financial Calculations
- Discounts and sales
- Tax calculations
- Interest rates
- Tips and gratuities
Academic Use
- Grade calculations
- Test scores
- Statistical analysis
- Research data
Business Applications
- Profit margins
- Market share
- Growth rates
- Performance metrics
Everyday Use
- Cooking and recipes
- Budgeting
- Time management
- Progress tracking
Example Calculations
Shopping Discount
Calculate 20% off a $80 item:
- 20% = 0.20
- 0.20 × $80 = $16 (discount amount)
- Final price: $80 - $16 = $64
Test Score
Calculate score when getting 45 out of 50 questions correct:
- 45 ÷ 50 = 0.90
- 0.90 × 100 = 90%
Tips and Tricks
- To quickly find 10%, move the decimal point one place to the left
- For 5%, take half of 10%
- 25% is the same as one-quarter, so divide by 4
- To find 1%, move the decimal point two places to the left
- Remember that percentages can be greater than 100% when the part is larger than the whole
- When working with money, always round to two decimal places