Back to QuickTools

Percentage Calculator

Calculate percentages, increases, decreases, and percentage changes easily.

Common Percentage Calculations
Quick reference for percentage formulas

What % of X is Y?

(Y / X) × 100

Example: What % of 200 is 50? → (50 / 200) × 100 = 25%

What is X% of Y?

(X / 100) × Y

Example: What is 25% of 200? → (25 / 100) × 200 = 50

Percentage Increase

Original + (Original × Percentage / 100)

Example: Increase 100 by 20% → 100 + (100 × 20 / 100) = 120

Percentage Change

((New - Old) / Old) × 100

Example: From 100 to 120 → ((120 - 100) / 100) × 100 = 20%

Percentage Tips

  • A percentage is a way to express a number as a fraction of 100. The symbol % means "per hundred".

  • Percentages are used in discounts, taxes, interest rates, statistics, and many everyday calculations.

  • To find 10% of any number, just move the decimal point one place to the left. For 1%, move it two places.

  • A change from 10% to 15% is a 5 percentage point increase, but a 50% relative increase.

  • To quickly calculate 15%, find 10% (move decimal left) then add half of that amount.

  • When comparing percentages, always check if it refers to the same base - percentages of different totals mean different amounts.