🔄 Converters
Converters translate between units across length, area, volume, weight, temperature, speed, time, data and more. Each converter uses exact international definitions where they exist: the metre, the kilogram, the 1959 international yard and pound agreement, and the SI brochure. Enter one value and read every equivalent instantly, with precision that stays traceable to the standard rather than rounded intermediates. Conversion tables for common everyday values are included, along with tips for mental conversions. All converters run entirely in your browser. If you are working to a standard, check the unit conventions that standard expects, because a few fields still use historical local measures alongside the SI values. The converters share one interface, so once you have used one, the rest feel familiar, and every page links to the related conversion tools in the same family.
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Area Converter
Convert square measurements between metric, imperial, acres, and hectares.
Knots to MPH Converter
Convert knots, miles per hour, kilometres per hour, metres per second, and feet per second, nautical, road, and aviation speeds.
HEX to HSL Color Converter
Convert a 6-digit or 3-digit hex colour to HSL (Hue, Saturation, Lightness) using the W3C CSS Color Module Level 4 algorithm, with live swatch, WCAG contrast, and palette generation.
Hex to RGB Converter
Convert hex colour codes to RGB, HSL, CMYK, and a live preview swatch.
ASCII to Hex Converter
Convert ASCII text to hexadecimal bytes and back, bidirectional encoder/decoder.
ASCII to Text Converter
Decode a stream of ASCII codes (decimal, hex, octal, or binary) back into readable text with separator and prefix options.
Unit Converter
Length, weight, volume, temperature, and more.
Temperature Converter
Celsius, Fahrenheit, and Kelvin.
Length Converter
Convert between km, miles, feet, inches, and more.
Weight Converter
Convert between kg, lbs, stone, and more.
Speed Converter
Convert between mph, km/h, m/s, and knots.
Roman Numeral Converter
Convert between Roman numerals and numbers.
Shoe Size Converter
Convert shoe sizes between US, UK, and EU.
Color Converter
Convert any color between HEX, RGB, HSL, and HSV/HSB. Live swatch, per-format validation, and quick presets for common web colors.
Centimetre ⇄ Millimetre ⇄ Inch Converter
Bidirectional cm ⇄ mm ⇄ inches with metres and feet read-outs.
Tyre Size Calculator
Tyre diameter, circumference, and speedometer error from size codes.
Clothing Size Converter
International clothing and shoe sizes across US, UK, EU, JP, and AU.
Ring Size Converter
Convert ring sizes between US, UK, EU systems with diameter chart.
Data Storage Converter
Convert between digital storage units instantly.
Energy Converter
Convert between energy units, joules, kilojoules, kilowatt-hours, BTUs, calories, kilo...
Power Converter
Convert between power units, watts, kilowatts, megawatts, horsepower, BTU/hour, and more.
Celsius to Fahrenheit Converter
Convert Celsius to Fahrenheit and Fahrenheit to Celsius instantly. Bidirectional sync with quick-preset reference points.
Cups to Grams Converter
Convert US cups to grams (and back) for eight common baking ingredients, water, flour, sugar, butter, honey, olive oil, milk, and rice, with bidirectional sync.
Stone to Kilograms Converter
Convert stones to kilograms and kilograms to stones instantly with the full UK body-weight breakdown (1 st = 14 lb = 6.35029318 kg = 224 oz).
BTU to Watts Converter
Convert BTU per hour to watts and watts to BTU/h instantly. Bidirectional sync with HVAC presets for window AC, central AC, heat pumps, and space heaters.
Lumens to Watts Converter
Convert lumens to watts and watts to lumens instantly with luminous-efficacy presets for incandescent, halogen, CFL, LED, and high-efficiency LED light sources.
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal instantly. Pick a source base, type a value, and read the same number in all four bases.
Shoe & Clothing Size Converter
Convert shoe and clothing sizes between US, UK, EU, JP, AU, and more.
Feet & Meters Converter
Convert between feet, metres, inches, yards, miles and all length units.
CM to MM Converter
Convert between millimetres, centimetres, metres, and inches with sub-mm precision.
Barcode Generator
Generate Code 128, Code 39, EAN-13, and UPC-A barcodes client-side. Download as SVG or PNG.
Aspect Ratio Calculator
Calculate width and height while maintaining an aspect ratio. Presets for 16:9, 4:3, 21:9, 1:1, 4:5, 9:16, plus custom ratios.
Digital Storage Converter
Convert between bits, bytes, KB, MB, GB, TB, KiB, MiB, GiB, TiB, decimal (SI) and binary (IEC) modes.
Fuel Efficiency Converter
Convert between L/100km, MPG (US), MPG (UK), and km/L instantly.
Gauge to mm Converter
Convert AWG wire gauge and sheet-metal gauge to millimetres and inches. Material-specific sheet tables (steel, aluminium), AWG reverse lookup, mm² area.
Torque Converter
Convert torque between newton-metres (N·m), kilogram-force metres (kgf·m), pound-force feet (lbf·ft), pound-force inches (lbf·in), and ounce-force inches (ozf·in). Five synced fields with fastener presets.
CSV to JSON Converter
Convert CSV to JSON in your browser. RFC 4180 parser handles quoted commas, newlines and escaped quotes. Pick delimiter, header, trim and type coercion.
Data Transfer Rate Converter
Convert any data transfer rate between bit/s, kbit/s, Mbit/s, Gbit/s, Tbit/s, byte/s, kB/s, MB/s, GB/s and the IEC binary set KiB/s, MiB/s, GiB/s, all pivoted through bit/s so twelve fields stay in sync. Includes a download-time panel.
Flow Rate Converter
Convert volumetric flow rate between m³/s, m³/h, L/s, L/min, L/h, US GPM, US GPH, Imperial GPM, ft³/s (CFS) and ft³/min (CFM). Ten synced fields plus a pipe-velocity panel.
Viscosity Converter
Convert dynamic viscosity (Pa·s, mPa·s, poise, cP, lbf·s/ft², lb/(ft·s)) and kinematic viscosity (m²/s, stokes, cSt, mm²/s, ft²/s) with a density bridge between the two panels.
Magnetic Field Converter
Convert magnetic flux density (T, mT, µT, G, mG, γ), magnetic flux (Wb, Mx), and magnetic field strength (A/m, Oe). Includes a free-space B↔H bridge and a reference table of real-world field magnitudes.
Radiation Dose Converter
Convert absorbed dose (gray, rad), equivalent dose (sievert, rem, mSv, µSv, mrem), activity (becquerel, curie) and exposure (C/kg, roentgen) across four independent panels.
Braille Translator
Convert plain text to and from Grade-1 Braille Unicode instantly in your browser, letters, numbers, and punctuation with copy-paste support.
Kilometers to Miles Converter
Convert kilometres to statute miles (and miles to kilometres) instantly using the exact 1.609344 km/mi factor. Includes pace and metres/feet/yards read-outs.
Meters ⇄ Yards Converter
Convert metres to yards and yards to metres instantly using the exact 0.9144 m/yd factor. Shows centimetres, millimetres, feet and miles too.
RGB to Hex Converter
Convert RGB colour values (0 to 255 per channel) to a hex code and back, with a live preview swatch.
Pint to Litre Converter
Convert pints to litres (and litres to pints) for both UK imperial and US liquid pints. Live cross-update with fl oz and mL read-outs.
Kilograms to Stones Converter
Convert kilograms to UK stones (and back) using the exact factor 1 stone = 14 pounds = 6.35029318 kg. Shows canonical "X st Y lb" form for body weight plus bonus read-outs in kg, g, lb, oz and US short tons.
Text to ASCII Converter
Convert any text to its ASCII code points in decimal, hex, or binary, and decode a numeric code stream back into text. Includes a per-character breakdown.
Miles to Yards Converter
Convert between miles and yards with full precision. 1 mile = 1 760 yards exactly.
Liters to Gallons Converter
Bidirectional litre ↔ US/UK gallon converter with strict NIST factors and cross-displayed millilitres.
Binary to Octal Converter
Convert binary to octal instantly using the 3-bit grouping shortcut, and see decimal and hexadecimal at the same time. Shows the padded bit groups step by step, validates every digit, and uses BigInt so long bit strings stay exact.
Cups to Tablespoons Converter
Convert US cups to tablespoons (and back) instantly. 1 US cup = 16 US tablespoons exactly. Bonus readouts for teaspoons, fluid ounces, and millilitres.
Yards ⇄ Feet Converter
Convert yards to feet and feet to yards instantly. 1 yard = 3 feet exactly (NIST SP 811). Includes metres, centimetres, millimetres, kilometres, inches, and miles bonus read-outs with a results table.
Hex to Binary Converter
Convert hexadecimal to binary using the exact 4-bit grouping shortcut, with octal and decimal shown alongside. Shows the padded nibble groups step by step, validates every digit, and uses BigInt so long hex strings stay exact.
Pounds to Stones Converter
Convert pounds to stones and stones + pounds to kilograms using the exact UK definition (1 st = 14 lb, 1 lb = 0.45359237 kg by the 1959 international yard-and-pound agreement). Shows kg, g, oz, US short tons alongside.
Miles to Kilometers Converter
Convert statute miles to kilometres and vice versa using the exact factor 1 mi = 1.609344 km (international yard-and-pound agreement of 1959). Bonus read-outs in metres, feet and yards.
Inches to Centimeters Converter
Convert inches to centimetres and vice versa using the exact factor 1 in = 2.54 cm (international yard-and-pound agreement of 1959). Bonus read-outs in mm, m, feet and yards.
Joules ⇄ BTU Converter
Convert joules to BTU (International Table) and BTU to joules. 1 BTU(IT) = 1 055.05585262 J exactly (NIST SP 811). Bonus read-outs in kJ, kWh, cal, kcal, ft·lbf.
Hex to Decimal Converter
Convert hexadecimal numbers (0x...) to decimal, binary, and octal instantly with strict input validation.
Decimal to Hex Converter
Convert decimal (base-10) integers to hexadecimal, binary, and octal instantly with strict input validation.
Octal to Decimal Converter
Convert octal numbers (0o...) to decimal, binary, and hex instantly with strict input validation, perfect for Unix file permissions.
Milligrams to Grams Converter
Convert milligrams (mg) to grams (g) and back, with quick presets for medicine doses, kitchen measures, and chemistry lab quantities.
Days to Hours Converter
Convert days (d) to hours (h) and back, with quick presets for shifts, weeks, months, and years.
Watts to Kilowatts Converter
Convert watts (W) to kilowatts (kW) and back, with quick presets for appliances, lighting, heaters, and small industrial loads.