Percentage Calculator

Percentage Formulas

What is P% of X?

y = (X × P) ÷ 100. Example: 20% of 150 = (150 × 20) ÷ 100 = 30. Used for calculating discounts, tips, tax amounts, and commission.

X is what % of Y?

P = (X ÷ Y) × 100. Example: 30 is what % of 150 = (30 ÷ 150) × 100 = 20%. Used for calculating test scores, market share, and completion rates.

X is P% of what?

Y = (X × 100) ÷ P. Example: 30 is 20% of what = (30 × 100) ÷ 20 = 150. Useful when you know the result and the percentage, but not the original number.

Increase / Decrease by P%

Increase: Y = X × (1 + P/100). Decrease: Y = X × (1 − P/100). Example: 150 increased by 20% = 150 × 1.20 = 180. Used for price rises, salary increases, and VAT calculations.