Free Calculator
Percentage Calculator
Four types of percentage calculations in one place. Pick the mode, enter two numbers, and get the answer with a step-by-step formula instantly — no formula memorization needed.
Common percentage values
| % | of 100 | of 200 | of 500 | of 1000 |
|---|---|---|---|---|
| 5% | 5 | 10 | 25 | 50 |
| 10% | 10 | 20 | 50 | 100 |
| 15% | 15 | 30 | 75 | 150 |
| 20% | 20 | 40 | 100 | 200 |
| 25% | 25 | 50 | 125 | 250 |
| 30% | 30 | 60 | 150 | 300 |
| 40% | 40 | 80 | 200 | 400 |
| 50% | 50 | 100 | 250 | 500 |
| 75% | 75 | 150 | 375 | 750 |
What Can This Percentage Calculator Do?
Most percentage problems fall into one of four patterns. This tool handles all of them with clear explanations:
- What is X% of Y? — The most common type. Find a tip amount, a sale discount, a tax figure, or any part of a whole. Enter the percentage and the base number and the result appears instantly.
- X is what % of Y? — Find the relative size of one number compared to another. Useful for test scores (you got 42 out of 55, what percent is that?), market share, and ratio comparisons.
- Percentage change — Calculate how much something grew or shrank between two values. From price changes to population growth to exam score improvements, percentage change tells you the relative difference.
- Reverse percentage — Work backwards from a known result. If a shirt is $48 after a 20% discount, what was the original price? Enter 20% and 48, and the calculator finds 60.
Everyday Uses of Percentage Calculations
Percentages appear in almost every area of daily life. Understanding how to calculate them quickly has real practical value:
- Shopping: Calculate sale discounts, cashback amounts, and VAT or sales tax
- Finance: Interest rates, investment returns, mortgage rate changes, and budget splits
- Education: Grade percentages, test score conversions, and attendance rates
- Health & fitness: Body fat percentage, daily macro splits, and progress tracking
- Business: Profit margins, conversion rates, growth percentages, and commission calculations
- Data analysis: Population changes, survey results, and comparative statistics
How Percentage Formulas Work
The word "percent" comes from Latin per centum, meaning "per hundred." Every percentage is a fraction with 100 as the denominator:
- X% of Y = (X ÷ 100) × Y
- X is what % of Y = (X ÷ Y) × 100
- Percentage change = ((New − Old) ÷ |Old|) × 100
- Reverse: X% of ? = Y = Y ÷ (X ÷ 100)
The calculator shows you the formula for every result, so you can verify the math or reuse it in a spreadsheet. For unit conversions alongside numerical work, see the unit converter. For displaying data on paper, the graph paper generator creates coordinate axes for plotting percentage data visually.