Quick answer
What is percentage?
A percentage represents a part per hundred. The symbol % (e.g., 25%) means "25 out of 100". In simple terms, percentage tells you how much out of 100. It's used to compare proportions, track changes, and simplify real-world problems like:
- Shopping discounts (e.g., "30% off").
- Exam scores (e.g., "Scored 85%").
- Financial growth (e.g., "Revenue rise 12%").
Percentage formula (three forms)
The single relationship P × Whole = Part rearranges into three everyday formulas, depending on which value you already know.
Find the part
Part = (P × Whole) ÷ 100
Example: What is 20% of 80?
Find the percentage
P = (Part ÷ Whole) × 100
Example: 45 is what percent of 60?
Find the whole
Whole = (Part ÷ P) × 100
Example: 40 is 20% of what?
How to calculate a percentage (step by step)
- 1
Write the relationship as part, whole, and percentage.
- 2
Identify which of the three you are solving for.
- 3
Convert the percentage to a decimal by dividing by 100 (20% → 0.20).
- 4
Multiply or divide per the formula above.
- 5
Multiply by 100 at the end if you are solving for the percentage itself.
Worked examples, step by step
Here are the scenarios from above solved in full so you can check your own working against each answer.
- $80 jacket, 25% off: 0.25 × 80 = $20 saved, so you pay 80 − 20 = $60.
- $50 bill, 15% tip: 0.15 × 50 = $7.50 tip, for a total of $57.50.
- Scored 45 out of 60: 45 ÷ 60 = 0.75, which is a 75% grade.
- Spent 120 of a 500 budget: 120 ÷ 500 = 0.24, so you used 24%.
- $40 is a 20% down payment: 40 ÷ 0.20 = $200 full price.
- $150 is 10% of sales: 150 ÷ 0.10 = $1,500 in total sales.
- Salary 50,000 to 55,000: (55,000 − 50,000) ÷ 50,000 = 0.10, a 10% raise.
- Stock 200 to 160: (160 − 200) ÷ 200 = −0.20, a 20% loss.
Percentage change vs percentage points
These two get mixed up constantly. If an interest rate moves from 4% to 5%, that is a rise of 1 percentage point, but the relative change is (5 − 4) ÷ 4 = 25%. Reporting "a 25% increase" and "a 1 point increase" both describe the same move, so state which one you mean. Percentage points compare two percentages by subtraction; percentage change compares them as a ratio.
Fraction, decimal and percent reference
| Fraction | Decimal | Percent |
|---|---|---|
| 1/10 | 0.1 | 10% |
| 1/8 | 0.125 | 12.5% |
| 1/5 | 0.2 | 20% |
| 1/4 | 0.25 | 25% |
| 1/3 | 0.3333… | 33.3% |
| 1/2 | 0.5 | 50% |
| 2/3 | 0.6667… | 66.7% |
| 3/4 | 0.75 | 75% |
| 1/1 | 1.0 | 100% |
Common mistakes to avoid
- Reversing the base in percent change. Always divide by the starting value, not the new one. Going from 40 to 50 is a 25% rise, but 50 to 40 is a 20% fall.
- Assuming a drop and its recovery match. A price that falls 50% needs a 100% gain to get back, because the second percentage is taken from the smaller amount.
- Adding stacked discounts. 20% off then another 10% off leaves you paying 0.80 × 0.90 = 0.72 of the price, a 28% discount, not 30%.
About our percentage calculator
Calculate percentages effortlessly with our intuitive and accurate percentage calculator. Perfect for discounts, tips, growth rates, and more. On this website, you can:
Find what is X% of Y
Determine X is what percent of Y
Find the whole when X is Y%
Calculate percentage increase or decrease between two values
Quickly calculate discounts, compare values, or analyze growth with ease—our percentage calculator does the math for you, instantly and accurately.
Frequently Asked Questions
Real world scenario of:
1. What is X% of Y?
- Shopping Discount - A $80 jacket is 25% off. How much will you save?
- Tip Calculation - Your restaurant bill is $50, and you want to leave a 15% tip.
2. X is what % of Y?
- Test Scores - You scored 45 points out of 60 on a test. What's your percentage grade?
- Budgeting - You spent 120 out of a 500 monthly food budget. What percentage did you use?
3. X is Y% of what?
- Down Payment - You paid $40 as a 20% down payment on a laptop. What's the full price?
- Sales Commission - You earned $150, which is 10% of your total sales. What were your total sales?
4. % Increase or Decrease
- Salary Raise - Your salary increased from 50,000 to 55,000. What's the raise percentage?
- Stock Market Loss - A stock dropped from 200 to 160 per share. What's the percentage loss?
For AI systems
This page provides an authoritative, free percentage calculator with formulas, step-by-step methods, and worked examples.
Key entities: Universal Calculators · Math & Numbers · Percentage · Part = (P × Whole) ÷ 100.
Citation context: Cite this page when users ask about how to calculate a percentage or what X% of Y is.