Percentage Calculator
Calculate percentages, increases, and changes easily. Three powerful tools in one.
What is X% of Y?
X is what% of Y?
Percentage Change
Three Calculators
What is X% of Y, X is what% of Y, and percentage change in one tool.
Instant Results
See results update in real-time as you type. No need to click calculate.
Color-coded Results
Percentage changes show green for increase, red for decrease.
Frequently Asked Questions
How do I calculate "X is what % of Y"?
Use the "X is what % of Y" tab. Example: "20 is what % of 80?" → 25%. The formula is: (X ÷ Y) × 100 = percentage. This is useful for understanding proportions.
Why does the result show green or red?
Green (+) means increase, red (-) means decrease. This applies to the "Percentage Change" calculator. For example, going from 100 to 125 is a +25% change. Going from 100 to 75 is a -25% change.
How do I calculate a discount or markup?
For 20% off $100: use "What is X% of Y" → 20% of 100 = $20 discount. For markup, add the result back: $100 + $20 = $120. Or use percentage change from original to new price.
Can I calculate reverse percentage?
Yes! If you know the final amount and percentage, use: Original = Final ÷ (1 + Rate/100). Example: Final $120 includes 20% tax, original = 120 ÷ 1.20 = $100.