What is X% of Y?
Percentage Increase
Percentage Decrease
What is a Percentage?
A percentage is a way of expressing a number as a fraction of 100. It's commonly used to compare proportions, calculate discounts, track growth, and analyze data in everyday life, business, and academics.
Key Formulas
X% of Y: (X ÷ 100) × Y
Increase: ((New - Old) ÷ Old) × 100
Decrease: ((Old - New) ÷ Old) × 100
When calculating percentage change, always use the original value as your denominator. A 50% increase followed by a 50% decrease doesn't return to the original value—math is tricky!
Quick Reference
Common Percentages
Real-World Uses
Percentage calculations are essential for: calculating sales tax and discounts, understanding interest rates, analyzing business growth, interpreting statistics, grading systems, and making informed financial decisions in daily life.
Learn More About Percentage Calculations
Master percentage calculations with our step-by-step Percentage Calculator Guide — includes percentages, discounts, increases, decreases, and real-world examples! 📚
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