--- title: "What is X% of Y? Free Online Percentage Calculator | ShoutingNow" description: "Solve everyday percentage problems in one place - find what is X% of Y, compare two values, or work out increases and decreases." url: "https://shoutingnow.com/tools/percent-calculator/" image: "https://shoutingnow.com/wp-content/uploads/2026/07/shoutingnow-preview-scaled.webp" --- # What is X% of Y? Free Online Percentage Calculator Solve everyday percentage problems in one place. Find what is X% of Y, compare two values, or work out an increase or decrease. Leave one field blank and the calculator fills it in for you. ## How to use this percentage calculator 1. For a plain percent of a number, type a percentage and a base value, then click Calculate. You can also leave any one of the three fields empty and let the tool solve for it. 2. Prefer plain language? Use the quick forms for “what is X% of Y,” “X is what % of Y,” and “X is Y% of what.” 3. To compare two values, use the percentage difference panel, which measures the gap relative to their average. 4. To model growth or decline from a starting value, or to work backward from a final amount, use percentage change. ## What is a percentage? A percentage is just a number written as a fraction of 100. The % symbol means “per hundred,” so 25% is the same thing as 25 per 100, or 0.25 written as a decimal. You will run into percentages constantly: discounts, tax rates, test scores, growth metrics, pretty much any comparison scaled to a familiar base. If the formulas below are new to you, read [How to Calculate Percentage: Simple Formulas with Examples](https://shoutingnow.com/blog/how-to-calculate-percentage/) for step-by-step walkthroughs and practice problems. ## Core percentage formula The relationship between a percentage *P*, a base value *V1*, and a result *V2* looks like this: Type “25% of 80” and the calculator converts 25% to 0.25, then multiplies: 0.25 × 80 = 20. ## Percentage difference vs. percentage change **Percentage difference** compares two values symmetrically against their average. **Percentage change** measures movement away from a starting point. Reach for change when you care about growth from a baseline, and reach for difference when neither number is clearly the “original.” ## Practical examples - Sale price: Taking 30% off $120 means entering 30% of 120, which gives you $36 off, for a final price of $84. - Test score: Getting 42 correct out of 50 means asking “42 is what % of 50,” which comes out to 84%. - Pay raise: A $55,000 salary increased by 4% means a starting value of 55000 and an increase of 4%, landing at $57,200. ## Examples and use cases ### Real-world use cases - Retail markdown: A store manager checks that a 25% clearance plus an extra 10% coupon actually matches the stacked discount math before the signage goes up. - Grade improvement: A student works out what score they need on a final exam to pull their course average from 78% up to 85%. - Business KPIs: A marketing lead tracks month-over-month traffic growth as a percentage change to report campaign performance to leadership. ## Frequently Asked Questions ### How do I calculate a percentage of a number? Multiply the number by the percentage divided by 100. For example, 15% of 200 is 200 × (15 ÷ 100) = 30. Use the "Percent of a number" panel above and just leave the result blank; the calculator fills it in. Our [percentage formulas guide](https://shoutingnow.com/blog/how-to-calculate-percentage/) has more worked examples if you want them. ### Can I leave one field blank? Yes. In the main percentage panel and the percentage change panel, enter exactly two values and leave the third empty. The tool figures out the missing number on its own. ### What is the difference between percentage difference and percentage change? Percentage change measures growth or decline from a specific starting value. Percentage difference compares two values against their average instead, without treating either one as the original. ### How do I find what percent one number is of another? Divide the part by the whole, then multiply by 100. For instance: 18 is what % of 72? 18 ÷ 72 × 100 = 25%. The "is what % of" quick form above does this for you. ### Does this calculator work on mobile? Yes. Every panel is touch-friendly and runs entirely in your browser, no download or account needed. Results update the moment you tap Calculate. ### Can I enter numbers with % or comma separators? Yes, values like 12.5%, 1,250, or plain decimals all work fine. The calculator strips out the formatting before it does the math. ```json [{"@context":"https://schema.org","@type":"Organization","name":"ShoutingNow","url":"https://shoutingnow.com/","logo":{"@type":"ImageObject","url":"https://shoutingnow.com/wp-content/themes/shoutingnow-theme/assets/images/logo.png"},"sameAs":["https://x.com/makani20","https://www.linkedin.com/in/makani20/","https://post-see.com"],"contactPoint":{"@type":"ContactPoint","contactType":"customer support","email":"support@shoutingnow.com","url":"https://shoutingnow.com/contact/"},"slogan":"Learn. Build. Grow."},{"@context":"https://schema.org","@type":"WebPage","name":"What is X% of Y? Free Online Percentage Calculator","description":"Solve everyday percentage problems in one place - find what is X% of Y, compare two values, or work out increases and decreases.","url":"https://shoutingnow.com/tools/percent-calculator/","inLanguage":"en-US"},{"@context":"https://schema.org","@type":"SoftwareApplication","name":"What is X% of Y? Free Online Percentage Calculator","description":"Solve everyday percentage problems in one place - find what is X% of Y, compare two values, or work out increases and decreases.","applicationCategory":"UtilitiesApplication","operatingSystem":"Web","url":"https://shoutingnow.com/tools/percent-calculator/","isAccessibleForFree":true,"offers":{"@type":"Offer","price":0,"priceCurrency":"USD","availability":"https://schema.org/InStock","url":"https://shoutingnow.com/tools/percent-calculator/"},"provider":{"@type":"Organization","name":"ShoutingNow","url":"https://shoutingnow.com/","logo":{"@type":"ImageObject","url":"https://shoutingnow.com/wp-content/themes/shoutingnow-theme/assets/images/logo.png"},"sameAs":["https://x.com/makani20","https://www.linkedin.com/in/makani20/","https://post-see.com"],"contactPoint":{"@type":"ContactPoint","contactType":"customer support","email":"support@shoutingnow.com","url":"https://shoutingnow.com/contact/"}}},{"@context":"https://schema.org","@type":"HowTo","name":"How to use What is X% of Y? Free Online Percentage Calculator","description":"Solve everyday percentage problems in one place - find what is X% of Y, compare two values, or work out increases and decreases.","url":"https://shoutingnow.com/tools/percent-calculator/","inLanguage":"en-US","step":[{"@type":"HowToStep","name":"For a plain percent of a number, type","text":"For a plain percent of a number, type a percentage and a base value, then click Calculate. You can also leave any one of the three fields empty and let the tool solve for it."},{"@type":"HowToStep","name":"Prefer plain language","text":"Prefer plain language? Use the quick forms for “what is X% of Y,” “X is what % of Y,” and “X is Y% of what.”"},{"@type":"HowToStep","name":"To compare two values, use the percentage difference","text":"To compare two values, use the percentage difference panel, which measures the gap relative to their average."},{"@type":"HowToStep","name":"To model growth or decline from a starting","text":"To model growth or decline from a starting value, or to work backward from a final amount, use percentage change."}]},{"@context":"https://schema.org","@type":"FAQPage","mainEntity":[{"@type":"Question","name":"How do I calculate a percentage of a number?","acceptedAnswer":{"@type":"Answer","text":"Multiply the number by the percentage divided by 100. For example, 15% of 200 is 200 × (15 ÷ 100) = 30. Use the \"Percent of a number\" panel above and just leave the result blank; the calculator fills it in. Our percentage formulas guide has more worked examples if you want them."}},{"@type":"Question","name":"Can I leave one field blank?","acceptedAnswer":{"@type":"Answer","text":"Yes. In the main percentage panel and the percentage change panel, enter exactly two values and leave the third empty. The tool figures out the missing number on its own."}},{"@type":"Question","name":"What is the difference between percentage difference and percentage change?","acceptedAnswer":{"@type":"Answer","text":"Percentage change measures growth or decline from a specific starting value. Percentage difference compares two values against their average instead, without treating either one as the original."}},{"@type":"Question","name":"How do I find what percent one number is of another?","acceptedAnswer":{"@type":"Answer","text":"Divide the part by the whole, then multiply by 100. For instance: 18 is what % of 72? 18 ÷ 72 × 100 = 25%. The \"is what % of\" quick form above does this for you."}},{"@type":"Question","name":"Does this calculator work on mobile?","acceptedAnswer":{"@type":"Answer","text":"Yes. Every panel is touch-friendly and runs entirely in your browser, no download or account needed. Results update the moment you tap Calculate."}},{"@type":"Question","name":"Can I enter numbers with % or comma separators?","acceptedAnswer":{"@type":"Answer","text":"Yes, values like 12.5%, 1,250, or plain decimals all work fine. The calculator strips out the formatting before it does the math."}}]},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"ShoutingNow","item":"https://shoutingnow.com/"},{"@type":"ListItem","position":2,"name":"Tools","item":"https://shoutingnow.com/tools/"},{"@type":"ListItem","position":3,"name":"What is X% of Y? Free Online Percentage Calculator","item":"https://shoutingnow.com/tools/percent-calculator/"}]}] ```