Percentage Calculator
Five ways to work with percentages — pick the mode that matches your question.
What is X% of Y?
% of=
30
Formula & Steps
result = (X / 100) × Y
= (15 / 100) × 200
= 0.15 × 200
= 30
Common Uses
Tax Calculator
Use "Add X% to Y" — add sales tax % to your subtotal.
Discount Calculator
Use "Subtract X% from Y" — apply a discount to original price.
Tip Calculator
Use "What is X% of Y" — calculate a tip amount.
Grade / Score
Use "X is what % of Y" — score out of total marks.
Price Change
Use "% change X → Y" — stock price, rent, salary changes.
Common Percentage Reference
| Fraction | Decimal | Percentage | Common use |
|---|---|---|---|
| 1/10 | 0.1 | 10% | Basic tip, simple markup |
| 1/8 | 0.125 | 12.5% | Tip, discount |
| 1/5 | 0.2 | 20% | Standard tip, tax |
| 1/4 | 0.25 | 25% | Quarter discount |
| 1/3 | 0.333… | 33.3% | One-third off |
| 1/2 | 0.5 | 50% | Half off |
| 2/3 | 0.666… | 66.7% | Two-thirds |
| 3/4 | 0.75 | 75% | Three-quarters |
All calculations run in your browser — nothing is sent to a server.