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Every unit, every color, exactly defined.

298 free unit converters across 12 categories and eight color tools — meters to feet, WCAG contrast, palettes and our own VersaScale engine. Instant results, the formula behind them, and the international definitions that make them exact.

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LengthConvert between metric and imperial length units: meters, kilometers, inches, feet, yards and miles. Instant results with exact internationally defined factors.56 converters · mm · cm · m · km · in · ft · yd · miWeightConvert between kilograms, grams, milligrams, metric tons, pounds and ounces. Exact internationally agreed factors for cooking, fitness, shipping and science.30 converters · mg · g · kg · t · oz · lbTemperatureConvert between Celsius, Fahrenheit and Kelvin with exact formulas. Instant results for cooking, weather, science and engineering.6 converters · °C · °F · KTimeConvert between milliseconds, seconds, minutes, hours, days, weeks, months and years. Exact SI-based factors, with standard averages for months and years.56 converters · ms · s · min · h · d · wk · mo · yrSpeedConvert between kilometers per hour, miles per hour, meters per second and knots. Exact factors for driving, aviation, sailing and physics.12 converters · km/h · m/s · mph · knDataConvert between bytes, kilobytes, megabytes, gigabytes, terabytes and petabytes. Decimal SI units (1 KB = 1,000 bytes), the standard used by storage manufacturers.30 converters · B · KB · MB · GB · TB · PBAreaConvert between square meters, square kilometers, square feet, hectares and acres. Exact factors for real estate, land surveying and agriculture.20 converters · m² · km² · ft² · ha · acVolumeConvert between milliliters, liters, cubic meters, US gallons and US fluid ounces. Exact internationally defined factors for cooking, fuel and science.20 converters · ml · L · m³ · gal · fl ozPressureConvert between pascals, bar, atmospheres, psi and millimeters of mercury. Exact factors for weather, diving, tires and engineering.20 converters · Pa · bar · atm · psi · mmHgEnergyConvert between joules, kilojoules, calories, kilocalories, kilowatt-hours and BTU. Exact factors for nutrition, electricity and heating.30 converters · J · kJ · cal · kcal · kWh · BTUFrequencyConvert between hertz, kilohertz, megahertz and gigahertz. Decimal SI factors for audio, radio, processors and networking.12 converters · Hz · kHz · MHz · GHzAngleConvert between degrees, radians and gradians. Exact factors for geometry, navigation, engineering and programming.6 converters · ° · rad · gon
Color toolsConvert hex, rgb, hsl, hsv, oklch and cmyk — plus a WCAG contrast checker and all 148 CSS color names.BlogGuides and explainers about units, measurement and converting with confidence.

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