Percentage Calculator
Quickly solve percentage problems with three calculation modes.
What is X% of Y?
How to Use
- Choose a calculation mode using the tabs at the top.
- Enter the two values needed for your chosen mode.
- Click "Calculate" to see the result instantly.
- Switch between modes to solve different types of percentage problems.
How It Works
Mode 1 — "What is X% of Y?": Multiplies Y by X/100. Mode 2 — "X is what % of Y?": Divides X by Y and multiplies by 100. Mode 3 — "X is Y% of what?": Divides X by Y/100. These three formulas cover all common percentage calculations you encounter in everyday math, finance, and statistics.
What Is a Percentage?
A percentage is a way of expressing a number as a fraction of 100. The word itself comes from the Latin "per centum," meaning "by the hundred." When you see 25%, that simply means 25 out of every 100. Percentages show up everywhere in daily life — from sales tax and restaurant tips to interest rates and exam scores. They give us a universal way to compare proportions, regardless of the original numbers involved.
This calculator handles the three most common percentage questions people run into. Whether you need to find a specific percentage of a number (like calculating a 20% tip), figure out what percentage one number is of another (like your test score), or work backward to find the original number before a percentage was applied (like the pre-sale price), this tool covers it all in one place.
Frequently Asked Questions
How do I calculate a percentage of a number?
To find X% of a number Y, multiply Y by X and then divide by 100. For example, 15% of 200 is (200 × 15) ÷ 100 = 30. You can also think of it as moving the decimal point two places to the left in the percentage and then multiplying.
What is the difference between percentage and percentile?
A percentage represents a portion out of 100, like scoring 85% on a test. A percentile, on the other hand, tells you how you rank compared to others. Being in the 90th percentile means you scored higher than 90% of all test-takers. They measure different things entirely.
How do I find the original price before a discount?
Use Mode 3 ("X is Y% of what?"). If an item costs $60 after a 25% discount, the sale price represents 75% of the original. Enter 60 as X and 75 as Y% to find the original price was $80. This works because the discounted price is always (100 − discount%) of the original.
Can I use this for percentage increase or decrease?
Yes. To find the percentage change, use Mode 2. Subtract the old value from the new value, then enter that difference as X and the old value as Y. The result tells you the percentage increase (if positive) or decrease (if negative). For example, going from 80 to 100 is a 25% increase.
Why does my calculator show a slightly different result?
This tool removes unnecessary trailing zeros for cleaner output, so 25.0000 displays as 25. The underlying math is the same. If you see minor differences from other calculators, it's usually due to rounding at different decimal places.
Example Calculation
Scenario:You're shopping and see a jacket originally priced at $120 with a 35% discount. How much do you save, and what's the final price?
Step 1: Use Mode 1 — "What is 35% of 120?" Enter 35 as the percentage and 120 as the number. Result: $42(that's your savings).
Step 2: Subtract the discount from the original price: $120 − $42 = $78 (the price you pay).
Verification:Use Mode 2 — "78 is what % of 120?" Result: 65%, which confirms the jacket is 65% of its original price (100% − 35% = 65%).