JSON.FORMATAll-in-one suite to format, validate, minify, diff compare, and convert JSON.//REGEX.TESTERReal-time regular expressions tester, cheatsheet, debugger and replacer.//PDF.SUITEMerge, split, extract text, rotate and convert PDF pages to images.//IMAGE.STUDIOIn-browser photo editor: crop, resize, filters, WebP/PNG and Base64 encoder.//HTML.BEAUTIFYHTML code beautifier, production minifier and entity encoder.//CSS.MINIFYCSS code formatter, production stylesheet minifier and CSS to SCSS converter.//SQL.FORMATTERSQL query beautifier, dialect translator (Postgres/MySQL) and minifier.//SVG.EXCALIDRAWInteractive vector visual editor powered by Excalidraw and SVG formatter.//TEXT.DIFFWord counter, reading time estimator and dual-text diff comparator.//YAML.CONVERTYAML & JSON bi-directional validator and formatter with syntax checking.//XML.PARSERXML document formatter, tree inspector and XML to JSON converter.//GRAPHQL.STUDIOGraphQL query & SDL formatter, minifier, AST field sorter and validator.//BASE64.CODECBase64 and URL-Safe encoder / decoder with full UTF-8 verification.//LOREM.IPSUMPlaceholder dummy text generator for mockups, prototypes and UI testing.//PASSWORD.GENCryptographically secure random password and entropy strength generator.//URL.STUDIO8-tool URL suite: encode, decode, validator, component parser and builder.//QR.STUDIOCustom QR code generator with embedded logos, colors, gradients and shapes.//ASCII.EXPLORERInteractive ASCII 0-255 table, Alt keyboard codes and CP437 symbols.//KEYCODES.LIVELive KeyboardEvent detector and JavaScript keycodes cheat sheet.//JWT.DEBUGGERJWT token decoder, claims inspector and Web Crypto signature verification.//BINARY.CODECBidirectional text to binary converter with digital rain and ASCII table.//CHARTS.STUDIOInteractive chart generator (bars, lines, pie, scatter) from CSV data.//UUID.V7Bulk generator for UUID v4, time-ordered v7, v1 and live UUID validator.//CSV.JSONBi-directional CSV to JSON converter with custom delimiters & table grid.//COLORS.STUDIOHEX/RGB/HSL/CMYK converter, palette harmonies and WCAG 2.1 contrast tester.//SEO.METASEO Meta Tags, Open Graph cards and real-time Google SERP card preview.//SCHEMA.JSONLDSchema.org JSON-LD structured data generator for Google Rich Snippets.//SITEMAP.XMLStandard XML Sitemap generator (Protocol 0.9) for Google Search Console.//ROBOTS.TXTRobots.txt generator, AI scraper blocking presets and live URL rule tester.//FAKE.DATASynthetic mock data generator: export records to JSON, CSV, SQL and TypeScript.//CLOCK.WORLDReal-time world clock with 3D holographic globe and 174 country timezones.//DATE.CALCDays between dates, exact age, business days, Unix timestamp and cron parser.//CALC.SUITESuite of 56+ online calculators: percentage, mortgage, loan, VAT, BMI & salary.//JSON.FORMATAll-in-one suite to format, validate, minify, diff compare, and convert JSON.//REGEX.TESTERReal-time regular expressions tester, cheatsheet, debugger and replacer.//PDF.SUITEMerge, split, extract text, rotate and convert PDF pages to images.//IMAGE.STUDIOIn-browser photo editor: crop, resize, filters, WebP/PNG and Base64 encoder.//HTML.BEAUTIFYHTML code beautifier, production minifier and entity encoder.//CSS.MINIFYCSS code formatter, production stylesheet minifier and CSS to SCSS converter.//SQL.FORMATTERSQL query beautifier, dialect translator (Postgres/MySQL) and minifier.//SVG.EXCALIDRAWInteractive vector visual editor powered by Excalidraw and SVG formatter.//TEXT.DIFFWord counter, reading time estimator and dual-text diff comparator.//YAML.CONVERTYAML & JSON bi-directional validator and formatter with syntax checking.//XML.PARSERXML document formatter, tree inspector and XML to JSON converter.//GRAPHQL.STUDIOGraphQL query & SDL formatter, minifier, AST field sorter and validator.//BASE64.CODECBase64 and URL-Safe encoder / decoder with full UTF-8 verification.//LOREM.IPSUMPlaceholder dummy text generator for mockups, prototypes and UI testing.//PASSWORD.GENCryptographically secure random password and entropy strength generator.//URL.STUDIO8-tool URL suite: encode, decode, validator, component parser and builder.//QR.STUDIOCustom QR code generator with embedded logos, colors, gradients and shapes.//ASCII.EXPLORERInteractive ASCII 0-255 table, Alt keyboard codes and CP437 symbols.//KEYCODES.LIVELive KeyboardEvent detector and JavaScript keycodes cheat sheet.//JWT.DEBUGGERJWT token decoder, claims inspector and Web Crypto signature verification.//BINARY.CODECBidirectional text to binary converter with digital rain and ASCII table.//CHARTS.STUDIOInteractive chart generator (bars, lines, pie, scatter) from CSV data.//UUID.V7Bulk generator for UUID v4, time-ordered v7, v1 and live UUID validator.//CSV.JSONBi-directional CSV to JSON converter with custom delimiters & table grid.//COLORS.STUDIOHEX/RGB/HSL/CMYK converter, palette harmonies and WCAG 2.1 contrast tester.//SEO.METASEO Meta Tags, Open Graph cards and real-time Google SERP card preview.//SCHEMA.JSONLDSchema.org JSON-LD structured data generator for Google Rich Snippets.//SITEMAP.XMLStandard XML Sitemap generator (Protocol 0.9) for Google Search Console.//ROBOTS.TXTRobots.txt generator, AI scraper blocking presets and live URL rule tester.//FAKE.DATASynthetic mock data generator: export records to JSON, CSV, SQL and TypeScript.//CLOCK.WORLDReal-time world clock with 3D holographic globe and 174 country timezones.//DATE.CALCDays between dates, exact age, business days, Unix timestamp and cron parser.//CALC.SUITESuite of 56+ online calculators: percentage, mortgage, loan, VAT, BMI & salary.//

MATH.PROP · MATH & PERCENTAGES

🔗 Proportion & Rule of Three Calculator

Rule of three and direct/inverse proportion solver (A/B = C/D). Solve for any unknown variable with clear step-by-step formulas.

⚙️ Known Values

A

B

C

⚡ Result (X)D = (B × C) / A

X =

125

D = (B × C) / A = 125

Frequently Asked Questions & Formulas

How does direct rule of three work?

If A corresponds to B, then C corresponds to X: X = (B * C) / A.

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