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Calculate percentages instantly with our free percentage calculator. Find percent of a number, calculate percentage change, increase or decrease values by a percentage, and more.
What is X% of Y?
Enter values to calculate percentage
Select the type of percentage calculation you need from the dropdown menu:
Input the required numbers in the appropriate fields. The calculator accepts decimals and negative numbers where applicable.
Click "Calculate" to see your result instantly. The answer is displayed with clear explanation of the calculation.
For sales and discounts, use "Decrease X by Y%" to find the final price after a discount. For tips, use "What is X% of Y?" to calculate the tip amount.
Result = (X / 100) × Y
Example: 25% of 80 = (25/100) × 80 = 20
Percent = (X / Y) × 100
Example: 20 is what % of 80? = (20/80) × 100 = 25%
Change = ((New - Old) / Old) × 100
Example: From 50 to 75 = ((75-50)/50) × 100 = 50% increase
Result = Value × (1 + X/100)
Example: 100 increased by 20% = 100 × 1.20 = 120
Result = Value × (1 - X/100)
Example: 100 decreased by 20% = 100 × 0.80 = 80
Percent = (Numerator / Denominator) × 100
Example: 3/4 = (3/4) × 100 = 75%
| Percentage | Fraction | Decimal | Ratio |
|---|---|---|---|
| 1% | 1/100 | 0.01 | 1:100 |
| 5% | 1/20 | 0.05 | 1:20 |
| 10% | 1/10 | 0.10 | 1:10 |
| 20% | 1/5 | 0.20 | 1:5 |
| 25% | 1/4 | 0.25 | 1:4 |
| 33.33% | 1/3 | 0.333 | 1:3 |
| 50% | 1/2 | 0.50 | 1:2 |
| 66.67% | 2/3 | 0.667 | 2:3 |
| 75% | 3/4 | 0.75 | 3:4 |
| 100% | 1/1 | 1.00 | 1:1 |
To find X% of Y, multiply Y by X and divide by 100. For example, 20% of 150 = 150 × 20 ÷ 100 = 30. You can also convert the percentage to a decimal first (20% = 0.20) and multiply: 150 × 0.20 = 30.
Subtract the old value from the new value, divide by the old value, then multiply by 100. Formula: ((New - Old) / Old) × 100. If the result is positive, it's an increase; if negative, it's a decrease. Example: From $50 to $75 = ((75-50)/50) × 100 = 50% increase.
To add X% to a number, multiply the number by (1 + X/100). For example, to add 15% to 200: 200 × (1 + 0.15) = 200 × 1.15 = 230. This is commonly used for calculating tax, tips, or price increases.
To find the sale price after a discount, multiply the original price by (1 - discount/100). For a 25% discount on $80: $80 × (1 - 0.25) = $80 × 0.75 = $60. The discount amount itself is $80 × 0.25 = $20.
A percentage is a portion out of 100 (e.g., 25% means 25 out of 100). A percentile indicates the position of a value in a dataset - the 90th percentile means 90% of values are below that point. They measure different things: percentage measures proportion, percentile measures ranking.
Divide the numerator by the denominator and multiply by 100. For example, 3/4 = 3 ÷ 4 = 0.75, then 0.75 × 100 = 75%. Another example: 2/5 = 2 ÷ 5 = 0.40 = 40%.
Use the formula: ((New Value - Original Value) / Original Value) × 100. For example, if a stock went from $40 to $52: ((52-40)/40) × 100 = 30% increase.
To find X% of Y%, multiply the two percentages and divide by 100. For example, 50% of 80% = (50 × 80) / 100 = 40%. This is useful in compound calculations.
Percentages are a way to express a number as a fraction of 100. The word "percent" comes from the Latin "per centum," meaning "by the hundred." Percentages are used everywhere in daily life: from calculating discounts and tips to understanding statistics, interest rates, and grades.
The concept of percentages makes it easy to compare proportions. For example, saying "25% of students passed" is clearer than "1 out of 4 students passed" or "0.25 of students passed."