Math

Percentage Calculator

Four percentage modes in one tool: find a percent of a number, determine what percent one number is of another, calculate percentage change, or convert between markup and margin.

Quick Answer

To find X% of Y, multiply Y by X/100 (e.g., 15% of 200 = 30). To find what percent X is of Y, divide X by Y and multiply by 100. Percentage change is calculated as ((new - old) / |old|) × 100. Markup and margin are different: a 50% markup on a $100 cost gives a $150 price, but the profit margin on that sale is 33.3%.

What is X% of Y?

Enter a percentage and a number to find the result.

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About This Tool

The Percentage Calculator is a versatile math tool that handles the four most common percentage calculations people search for every day. Whether you are a student working through homework, a business owner setting prices, or simply figuring out a discount while shopping, this calculator gives you instant, accurate results with the formula shown for every calculation.

Four Modes, One Calculator

“What is X% of Y?”is the most basic percentage operation. It answers questions like “What is 20% of 150?” (answer: 30). This is the mode you reach for when calculating discounts, tips, or tax amounts.

“X is what % of Y?” works in the other direction. If you scored 42 out of 50 on a test, this mode tells you that is 84%. It is also useful for understanding what fraction of a budget has been spent or what share of revenue comes from a particular product.

Percentage Change calculates the increase or decrease between two values. If your rent went from $1,200 to $1,350, that is a 12.5% increase. This mode works for tracking price changes, salary raises, population growth, or any before-and-after comparison.

Understanding Markup vs. Margin

Markup and margin are two different ways of expressing profit as a percentage, and confusing them is one of the most expensive mistakes in business. Markup measures profit relative to cost: if an item costs $60 and sells for $100, the markup is 66.7%. Margin measures profit relative to the selling price: for the same item, the margin is 40%. The markup percentage is always higher than the margin percentage for the same product. This converter shows both side by side so there is never any confusion. Retailers, restaurateurs, and ecommerce sellers use this daily to set prices that hit their profit targets.

Frequently Asked Questions

How do I calculate a percentage of a number?
To find X% of Y, convert the percentage to a decimal by dividing by 100, then multiply by the number. For example, 15% of 200 = (15/100) x 200 = 30. Our calculator does this instantly as you type.
What is the difference between markup and margin?
Markup is the percentage added to the cost price to get the selling price: (Selling - Cost) / Cost x 100. Margin is the percentage of the selling price that is profit: (Selling - Cost) / Selling x 100. A 50% markup equals a 33.3% margin. Markup is always higher than margin for the same product.
How do I calculate percentage increase or decrease?
Percentage change = ((New Value - Old Value) / |Old Value|) x 100. A positive result is an increase; a negative result is a decrease. For example, going from 80 to 100 is a 25% increase: ((100-80)/80) x 100 = 25%.
What does 'X is what percent of Y' mean?
This finds what fraction X represents of Y, expressed as a percentage. The formula is (X / Y) x 100. For example, 25 is 50% of 50, because (25/50) x 100 = 50%. This is useful for understanding proportions, test scores, discounts, and more.
Why is knowing the difference between markup and margin important for business?
Confusing markup and margin is one of the most common pricing mistakes. If your costs are $60 and you want a 40% margin, your selling price should be $100 (not $84). Using markup when you mean margin can cost your business thousands in lost profit. Always clarify which metric you are using when setting prices.