Percentage Calculator
Six different percentage calculations — all in one place, all instant.
① What is X% of Y?
② X is what % of Y?
③ Percentage Change
④ Increase a number by X%
⑤ Decrease a number by X%
⑥ Tip & Discount Calculator
How to Use the Percentage Calculator
This tool covers the most common percentage calculations you'll encounter in everyday life — from shopping discounts and tips to statistics and financial maths. Simply fill in the known values and the answer appears instantly.
How do I calculate a discount?
Use calculator ⑤ "Decrease a number by X%". Enter the original price and the discount percentage to find the discounted price.
How do I calculate percentage growth?
Use calculator ③ "Percentage Change". Enter the original value and the new value. A positive result means growth; negative means decline.
What is the formula for percentage?
Percentage = (Part ÷ Whole) × 100. For example, 25 out of 200 = (25÷200)×100 = 12.5%.
About the Percentage Calculator
Our free percentage calculator solves the three most common percentage problems instantly: finding what percentage one number is of another, calculating a percentage of a number, and finding the original number when you know a percentage of it. It also calculates percentage increase and decrease, making it useful for sales, finance, statistics, school maths, and everyday decisions.
Three Types of Percentage Calculations
- What is X% of Y? — Example: What is 15% of 80? Answer: 12. Used for calculating discounts, tips, tax amounts, and commission.
- X is what % of Y? — Example: 12 is what percentage of 80? Answer: 15%. Used for exam scores, survey results, and proportion analysis.
- X is Y% of what? — Example: 12 is 15% of what number? Answer: 80. Used for reverse calculations when you know the result and the percentage but need the original value.
Percentage Increase and Decrease
The calculator also handles percentage change: given a starting value and an ending value, it tells you the percentage increase or decrease. This is essential for comparing prices, investment returns, population changes, and business metrics over time.
- Percentage increase — If a price rises from €80 to €100, that's a 25% increase.
- Percentage decrease — If a salary drops from €50,000 to €45,000, that's a 10% decrease.
Common Uses for a Percentage Calculator
- Shopping discounts — Calculate the final price after a 20% sale discount.
- Restaurant tips — Quickly find 15%, 18%, or 20% of a bill total.
- VAT and sales tax — Add 20% VAT to a net price, or extract VAT from a gross price.
- Exam and test scores — Convert raw scores to percentages (e.g. 47 out of 60 = 78.3%).
- Investment returns — Calculate portfolio gain or loss as a percentage.
- Nutrition labels — Find what percentage of your daily calorie target a meal represents.
- Business reporting — Calculate month-over-month growth, margin percentages, and conversion rates.
Frequently Asked Questions
How do I calculate a percentage in my head?
For 10%: divide by 10. For 5%: divide by 20. For 20%: divide by 5. For 25%: divide by 4. For other percentages, use our calculator for instant precision.
What is the difference between percentage points and percent?
If interest rates rise from 3% to 5%, that's an increase of 2 percentage points, but a 66.7% increase in the rate itself. These are often confused in financial reporting.
How do I add VAT to a price?
Multiply the net price by (1 + VAT rate). For 20% VAT: multiply by 1.20. Our calculator handles this in the "What is X% of Y" mode.
Is the calculator free?
Yes, completely free with no limits and no account required.