Percentage Calculator: Master Percentage Calculations
Learn how to calculate percentages, percentage changes, and practical applications in everyday life and business.
2025-01-074 min
Understanding Percentages
A percentage is a number expressed as a fraction of 100. The word "percent" comes from Latin "per centum" meaning "by the hundred."
Common Percentage Calculations
What is X% of Y?
Formula: (X/100) × Y
Example: 20% of 150 = (20/100) × 150 = 30
X is what percent of Y?
Formula: (X/Y) × 100
Example: 30 is what % of 150? (30/150) × 100 = 20%
Percentage Change
Formula: ((New - Old) / Old) × 100
Example: 100 to 120 = ((120-100)/100) × 100 = 20% increase
Real-World Applications
Shopping Discounts
Original: $80, Discount: 25%
Sale Price = $80 × (1 - 0.25) = $60
Tips at Restaurants
Bill: $50, Tip: 18%
Tip Amount = $50 × 0.18 = $9
Tax Calculations
Price: $100, Tax: 8.5%
Total = $100 × (1 + 0.085) = $108.50
Investment Returns
Initial: $1000, Return: 7%
Final = $1000 × 1.07 = $1070