ToolFoxPercentage Calculator
Three percentage tools in one: X% of Y, X as a percentage of Y, and percentage change.
What is X% of Y?
- Result
- 270.00
X is what % of Y?
- Percentage
- 25.00%
Percentage change
- Change
- 25.00%
How it works
The three classic percentage questions each have a one-line formula: X% of Y = X × Y ÷ 100; "X is what % of Y" = X ÷ Y × 100; percentage change from old to new = (new − old) ÷ |old| × 100, negative when the value fell. All three update live as you type.
Example
An 18% tip on ₹1,500 is ₹270. Scoring 45 out of 180 is 25%. A price moving from ₹100 to ₹125 is a 25% increase; back to ₹100 from ₹125 is a 20% decrease — percentages are not symmetric.
Frequently asked questions
Why is +25% then −25% not back to the start?
Because the base changes: +25% of 100 → 125, but −25% of 125 → 93.75. Percentage change always uses the starting value as its base.
What are percentage points?
The absolute difference between two percentages (30% − 20% = 10 points), distinct from a 50% relative increase.
Can it handle decimals?
Yes — any real numbers work, with results shown to two decimal places.
Which formula for discounts?
"X% of Y" gives the discount amount; subtract it from the price (or compute Y × (1 − X/100)).
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