Percentages are everywhere in daily life — from shopping discounts to exam scores, tax calculations to investment returns. Understanding how to calculate percentages quickly is an essential skill that saves time and money.
What Is a Percentage?
A percentage represents a fraction of 100. The word "percent" literally means "per hundred." When you see 25%, it means 25 out of every 100, or one quarter.
Three Essential Percentage Formulas
1. Finding a percentage of a number: Multiply the number by the percentage divided by 100. For example, 20% of 150 = 150 × (20/100) = 30.
2. Finding what percentage one number is of another: Divide the part by the whole and multiply by 100. For example, 30 out of 150 = (30/150) × 100 = 20%.
3. Finding the original number from a percentage: Divide the result by the percentage and multiply by 100. If 20% of a number is 30, then the number = (30/20) × 100 = 150.
Common Percentage Calculations
Shopping discounts: A $80 item with 25% off costs $80 - ($80 × 0.25) = $60. Our Percentage Calculator handles this instantly.
Tip calculations: For a 15% tip on a $45 meal: $45 × 0.15 = $6.75. Total: $51.75.
Grade calculations: If you scored 42 out of 50: (42/50) × 100 = 84%.
Percentage increase/decrease: If a price went from $200 to $250: ((250-200)/200) × 100 = 25% increase.
Why Use Our Free Percentage Calculator?
Our online Percentage Calculator eliminates manual math errors and handles all percentage types instantly. It supports percentage of a number, percentage change, percentage difference, and reverse percentage calculations — all in one tool. No signup required, works on any device, and supports 30 languages.