--- title: "Hydroxide Ion Concentration Calculator | Chemistry Formula Calculator | XTRAW Tools" description: "Calculate [OH⁻] concentration from pOH or pH. Use this free browser-based chemistry calculator from XTRAW Tools for lab, classroom, and STEM estimates." url: "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator" date: "2026-05-21T23:55:11+00:00" language: "en-GB" --- [Z Score Calculator](https://xtraw.com/tools/calculators/z-score-calculator)[A/B Test Calculator](https://xtraw.com/tools/calculators/ab-test-calculator) [![Hydroxide Ion Concentration Calculator from XTRAW Tools](https://xtraw.com/images/virtuemart/product/xtraw-hydroxide-ion-concentration-calculator-360x360.jpg)](https://xtraw.com/images/virtuemart/product/xtraw-hydroxide-ion-concentration-calculator-360x360.jpg "Hydroxide Ion Concentration Calculator from XTRAW Tools") new [Back to: Calculators](https://xtraw.com/tools/calculators "Calculators") # Hydroxide Ion Concentration Calculator Calculate [OH⁻] concentration from pOH or pH. Use this free browser-based hydroxide ion concentration calculator from XTRAW Tools. **Hydroxide Ion Concentration Calculator** helps you calculate \[OH⁻\] concentration from pOH or pH. Use this free browser-based calculator from XTRAW Tools to compare inputs, estimate results, and plan your next step. ## How to Use the Hydroxide Ion Concentration Calculator 1. Enter the required calculator inputs shown in the form. 2. Review the chemistry, acid-base, titration, buffer, formula, decay, cell-potential, or reaction-rate assumptions. 3. Run the calculator, then adjust one input at a time to compare scenarios or check your estimate. ## What This Calculator Helps With Calculate \[OH⁻\] concentration from pOH or pH. It is designed for students, teachers, chemistry learners, lab users, healthcare reference users, STEM tutors, and anyone working with chemistry formulas who want a fast browser-based estimate before relying on a textbook, lab software, chemistry reference, professional source, or specialist. - Input: pOH - pOH: 5 - pH: 9 ## Common Uses People use this calculator when they need a quick way to estimate pH, pOH, hydrogen ion concentration, hydroxide ion concentration, acidity, or basicity. - **Math Solving:** Solve chemistry, pH, pOH, buffer, titration, formula, electrochemistry, decay, or reaction-rate equations from entered values. - **Measurement:** Measure ion concentration, buffer pH, titration concentration, freezing point change, molecular formula ratios, decay values, or cell potential. - **Health Estimate:** Review acid-base and chemistry reference values for general education only, not for clinical or medical decisions. - **Project Planning:** Plan lab estimates, solution preparation, STEM assignments, chemistry study workflows, or classroom problem-solving tasks. ## Formula or Method \[OH⁻\] = 10^(−pOH); pOH = 14 − pH ## Example **Example inputs:** Input: pOH; pOH: 5; pH: 9 **Example result:** Using the default pOH of 5, \[OH⁻\] is about 1.0000e-05 mol/L. ## Related Tools - [pH Calculator](https://xtraw.com/tools/ph-calculator) - [pOH Calculator](https://xtraw.com/tools/poh-calculator) - [Hydrogen Ion Concentration Calculator](https://xtraw.com/tools/hydrogen-ion-concentration-calculator) - [Henderson-Hasselbalch Calculator](https://xtraw.com/tools/henderson-hasselbalch-calculator) - [Buffer pH Calculator](https://xtraw.com/tools/buffer-ph-calculator) ## Hydroxide Ion Concentration Calculator FAQ ### Is the Hydroxide Ion Concentration Calculator free? Yes. This calculator is free to use on XTRAW Tools. ### Do I need to create an account? No. XTRAW tools are designed for browser-based use without requiring an account. ### Are the results exact? Results may be estimates depending on the inputs, formula, rounding, chemistry reference values, assumptions, or purpose of the calculator. Always verify important results before relying on them. **Disclaimer:** This calculator is provided for general informational, educational, and convenience purposes only. It is not medical, laboratory, chemical handling, safety, legal, financial, academic, regulatory, nuclear safety, electrochemical engineering, or professional advice. Always verify important results with a qualified professional, instructor, chemist, lab supervisor, safety documentation, authoritative source, or appropriate specialist before making decisions. **Related Products** ![Tooltip]() [![pH Calculator from XTRAW Tools](https://xtraw.com/images/virtuemart/product/resized/xtraw-ph-calculator-360x360_230x230.jpg) pH Calculator](https://xtraw.com/tools/calculators/ph-calculator "pH Calculator") Calculate pH from hydrogen ion concentration or from pOH. Use this free browser-based ph calculator from XTRAW Tools. Custom prototype for related products [![pOH Calculator from XTRAW Tools](https://xtraw.com/images/virtuemart/product/resized/xtraw-poh-calculator-360x360_230x230.jpg) pOH Calculator](https://xtraw.com/tools/calculators/poh-calculator "pOH Calculator") Calculate pOH from hydroxide ion concentration or from pH. Use this free browser-based poh calculator from XTRAW Tools. Custom prototype for related products [![Hydrogen Ion Concentration Calculator from XTRAW Tools](https://xtraw.com/images/virtuemart/product/resized/xtraw-hydrogen-ion-concentration-calculator-360x360_230x230.jpg) Hydrogen Ion Concentration Calculator](https://xtraw.com/tools/calculators/hydrogen-ion-concentration-calculator "Hydrogen Ion Concentration Calculator") Calculate \[H⁺\] concentration from pH. Use this free browser-based hydrogen ion concentration calculator from XTRAW Tools. Custom prototype for related products [![Henderson-Hasselbalch Calculator from XTRAW Tools](https://xtraw.com/images/virtuemart/product/resized/xtraw-henderson-hasselbalch-calculator-360x360_230x230.jpg) Henderson-Hasselbalch Calculator](https://xtraw.com/tools/calculators/henderson-hasselbalch-calculator "Henderson-Hasselbalch Calculator") Calculate buffer pH using the Henderson-Hasselbalch equation. Use this free browser-based henderson-hasselbalch calculator from XTRAW Tools. Custom prototype for related products [![Buffer pH Calculator from XTRAW Tools](https://xtraw.com/images/virtuemart/product/resized/xtraw-buffer-ph-calculator-360x360_230x230.jpg) Buffer pH Calculator](https://xtraw.com/tools/calculators/buffer-ph-calculator "Buffer pH Calculator") Calculate the pH of a buffer solution from Ka, acid, and conjugate base concentrations. Use this free browser-based buffer ph calculator from XTRAW Tools. Custom prototype for related products **Related Categories** ![Tooltip]()[![Calculators category image](https://xtraw.com/images/virtuemart/category/2_calculators.jpg) Calculators](https://xtraw.com/tools/calculators "Calculators") Custom prototype for related categories [![Science Calculators category image](https://xtraw.com/images/virtuemart/category/26_science_calculators.jpg) Science Calculators](https://xtraw.com/tools/calculators/science-calculators "Science Calculators") Custom prototype for related categories [![Chemistry Calculators category image](https://xtraw.com/images/virtuemart/category/230_chemistry-calculators.jpg) Chemistry Calculators](https://xtraw.com/tools/calculators/science-calculators/chemistry-calculators "Chemistry Calculators") Custom prototype for related categories [![Acid-Base Calculators category image](https://xtraw.com/images/virtuemart/category/237_acid-base-calculators.jpg) Acid-Base Calculators](https://xtraw.com/tools/calculators/science-calculators/chemistry-calculators/acid-base-calculators "Acid-Base Calculators") Custom prototype for related categories [![Education Tools category image](https://xtraw.com/images/virtuemart/category/086_education_tools_350x350.jpg) Education Tools](https://xtraw.com/tools/industry-tools/education-tools "Education Tools") Custom prototype for related categories ## Schema ```json { "@context": "https://schema.org", "@graph": [ { "@type": "Organization", "@id": "https://xtraw.com#organization", "name": "XTRAW Tools", "alternateName": "XTRAW", "url": "https://xtraw.com", "logo": { "@type": "ImageObject", "@id": "https://xtraw.com#logo", "url": "https://xtraw.com/images/xtraw-logo.png#joomlaImage://local-images/xtraw-logo.png?width=1100&height=400", "contentUrl": "https://xtraw.com/images/xtraw-logo.png#joomlaImage://local-images/xtraw-logo.png?width=1100&height=400", "caption": "XTRAW Tools" }, "image": { "@id": "https://xtraw.com#logo" }, "email": "jason@vuumarketing.com", "description": "XTRAW Tools provides free browser-based calculators, converters, generators, developer tools, business tools, file tools, writing tools, and everyday utilities.", "knowsAbout": [ "calculators", "online calculators", "unit converters", "file tools", "developer tools", "business calculators", "finance calculators", "math calculators", "education calculators", "health calculators", "construction calculators", "real estate calculators", "writing tools", "random generators", "everyday utilities" ], "contactPoint": { "@type": "ContactPoint", "contactType": "customer support", "email": "jason@vuumarketing.com", "url": "https://xtraw.com/contact" } }, { "@type": "WebSite", "@id": "https://xtraw.com#website", "name": "XTRAW Tools", "alternateName": "XTRAW Tools", "url": "https://xtraw.com", "publisher": { "@id": "https://xtraw.com#organization" }, "inLanguage": "en-gb", "about": { "@id": "https://xtraw.com#organization" } }, { "@type": "ImageObject", "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#primaryimage", "url": "https://xtraw.com/https://xtraw.com/images/virtuemart/product/xtraw-hydroxide-ion-concentration-calculator-360x360.jpg", "contentUrl": "https://xtraw.com/https://xtraw.com/images/virtuemart/product/xtraw-hydroxide-ion-concentration-calculator-360x360.jpg", "caption": "Hydroxide Ion Concentration Calculator", "representativeOfPage": true }, { "@type": "WebPage", "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#webpage", "url": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator", "name": "Hydroxide Ion Concentration Calculator | Chemistry Formula Calculator | XTRAW Tools", "headline": "Hydroxide Ion Concentration Calculator", "description": "Calculate [OH⁻] concentration from pOH or pH. Use this free browser-based chemistry calculator from XTRAW Tools for lab, classroom, and STEM estimates.", "inLanguage": "en-gb", "isPartOf": { "@id": "https://xtraw.com#website" }, "publisher": { "@id": "https://xtraw.com#organization" }, "primaryImageOfPage": { "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#primaryimage" }, "datePublished": "", "dateModified": "", "mainEntity": { "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#webapplication" }, "about": { "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#webapplication" }, "breadcrumb": { "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#breadcrumb" } }, { "@type": "BreadcrumbList", "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#breadcrumb", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://xtraw.com/" }, { "@type": "ListItem", "position": 2, "name": "All Tools", "item": "https://xtraw.com/tools" }, { "@type": "ListItem", "position": 3, "name": "Hydroxide Ion Concentration Calculator", "item": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator" } ] }, { "@type": [ "WebApplication", "SoftwareApplication" ], "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#webapplication", "name": "Hydroxide Ion Concentration Calculator", "alternateName": "Hydroxide Ion Concentration Calculator | Chemistry Formula Calculator | XTRAW Tools", "description": "Calculate [OH⁻] concentration from pOH or pH. Use this free browser-based chemistry calculator from XTRAW Tools for lab, classroom, and STEM estimates.", "url": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator", "mainEntityOfPage": { "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#webpage" }, "image": "https://xtraw.com/https://xtraw.com/images/virtuemart/product/xtraw-hydroxide-ion-concentration-calculator-360x360.jpg", "thumbnailUrl": "https://xtraw.com/https://xtraw.com/images/virtuemart/product/xtraw-hydroxide-ion-concentration-calculator-360x360.jpg", "screenshot": { "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#primaryimage" }, "identifier": { "@type": "PropertyValue", "propertyID": "VirtueMart SKU", "value": "CALC-HYDROXIDE-ION-CONCENTRATION" }, "applicationCategory": "UtilitiesApplication", "applicationSubCategory": "", "genre": [ "Calculator", "Converter", "Web Tool", "Browser-Based Utility" ], "keywords": "hydroxide ion concentration calculator, hydroxide ion concentration calculator, OH- concentration from pOH; [OH-] formula; hydroxide concentration, science, XTRAW Tools, ", "operatingSystem": "Any operating system with a modern web browser", "browserRequirements": "Requires a modern web browser with JavaScript enabled.", "softwareRequirements": "No installation required. Browser-based tool.", "permissions": "No account required.", "softwareVersion": "XTRAW Tools Web", "datePublished": "", "dateModified": "", "isAccessibleForFree": true, "isFamilyFriendly": true, "creator": { "@id": "https://xtraw.com#organization" }, "publisher": { "@id": "https://xtraw.com#organization" }, "provider": { "@id": "https://xtraw.com#organization" }, "brand": { "@id": "https://xtraw.com#organization" }, "audience": { "@type": "Audience", "audienceType": "People looking for free browser-based calculators, converters, generators, and practical online tools." }, "featureList": [ "Free to use", "Browser based", "No signup required", "Instant results", "Mobile friendly", "Copyable results where supported", "", "", "" ], "offers": { "@type": "Offer", "@id": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator#free-offer", "url": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator", "price": "0", "priceCurrency": "USD", "availability": "https://schema.org/InStock", "category": "Free browser-based tool", "seller": { "@id": "https://xtraw.com#organization" }, "eligibleRegion": { "@type": "Place", "name": "Worldwide" } }, "potentialAction": { "@type": "UseAction", "name": "Use Hydroxide Ion Concentration Calculator", "target": { "@type": "EntryPoint", "urlTemplate": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator", "actionPlatform": [ "https://schema.org/DesktopWebPlatform", "https://schema.org/MobileWebPlatform", "https://schema.org/TabletWebPlatform" ] } } } ] } ``` ```json { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://xtraw.com" }, { "@type": "ListItem", "position": 2, "name": "All Tools", "item": "https://xtraw.com/tools" }, { "@type": "ListItem", "position": 3, "name": "Calculators", "item": "https://xtraw.com/tools/calculators" }, { "@type": "ListItem", "position": 4, "name": "Hydroxide Ion Concentration Calculator", "item": "https://xtraw.com/tools/calculators/hydroxide-ion-concentration-calculator" } ] } ```