Percentage Calculator Free Online
Three percentage operations in one tool: (1) what is X% of Y, (2) X is what percent of Y, (3) percent change from X to Y. Pick the operation, fill the two numbers.
Results
Pro — bulk batch calculation, API access, history & favorites
API access · Priority queue · Team workspace
Related Tools
Percentage Calculator Features
3 Modes
Percent of (discounts, tips), ratio (test scores, completion %), and percent change (price changes, growth rates).
Step Shown
Each result shows the equation: x% of y = (x/100) × y. Useful for homework or double-checking calculations.
Decimal & Fraction
Results shown as percentage, decimal, and (for ratios) approximate fraction.
Live Calculation
Switch modes or change values, results recalculate instantly.
Negative Change OK
Percent change handles negative shifts (e.g., -25%) and works correctly for negative starting values via |x|.
100% Private
All math runs in your browser.
Free vs Pro
| Feature | Free | Pro |
|---|---|---|
| Full percentage calculation | ||
| Live calculation | ||
| All-units result panel | ||
| Bulk batch calculation | — | |
| REST API access | — | |
| Save & share calculations | — |
Frequently Asked Questions
Multiply: (X ÷ 100) × Y. Example: 25% of 200 = 0.25 × 200 = 50. Or: 18% tip on $75 = (18/100) × 75 = $13.50.
((New − Old) ÷ |Old|) × 100. From 80 to 100 = (100 − 80) / 80 × 100 = 25% increase. From 100 to 80 = −20%.
So that going from −10 to +10 gives +200% (not -200%). Standard convention for percent-change calculations to make the sign indicate direction of movement.
Reverse percentage: (X ÷ Y) × 100. Example: 50 is what % of 200 = (50/200) × 100 = 25%. Useful for test scores: "I got 42 out of 60 = 70%".
Yes — they are not symmetric. -50% then +50% gives 0.75x (a 25% loss), not 1.0x. Use the change mode in two steps to verify.