Percentage Formulas
- X% of Y = (X/100) × Y
- X is what % of Y = (X/Y) × 100
- % change = ((New-Old)/Old) × 100
- Original from % increase = Final ÷ (1 + %/100)
How do I calculate 20% off a price?
Multiply the price by 0.20 to get the discount amount, then subtract from the original price. Or multiply the price by 0.80 to get the final price directly.
What is the percentage increase from 80 to 100?
(100-80)/80 × 100 = 25% increase.