Percentage Calculator

How to calculate a percentage

• X% of Y: multiply Y by X and divide by 100. Example: 15% of 80 = 80 × 15 / 100 = 12.
• X is what % of Y: divide X by Y and multiply by 100. Example: 12 is what % of 80 = 12/80 × 100 = 15%.
• % change: (New − Old) / |Old| × 100. A positive result is an increase; negative is a decrease.
• Add/subtract %: for a 20% increase, multiply by 1.2. For a 20% decrease, multiply by 0.8.

Common percentage examples

• Restaurant tip: 15% of $45 = $6.75
• Sales tax: $100 + 8% = $108
• Discount: $80 item with 25% off = $60
• Salary raise: $50,000 with 5% raise = $52,500