Unit Conversion Tools
Length, weight, temperature, volume, area, speed, time.
The standard conversion toolbox with a clean mobile layout. Each tool below supports both directions and a full set of common units.
Start here
Featured tools
Length Converter
Convert between meters, feet, inches, miles, kilometers, yards, and more.
Weight Converter
Convert between kilograms, pounds, ounces, grams, stones, and tons.
Temperature Converter
Convert between Celsius, Fahrenheit, Kelvin, and Rankine.
Volume Converter
Convert between liters, gallons, cubic meters, milliliters, cups, pints, and more.
Area Converter
Convert between square meters, square feet, acres, hectares, and more.
Speed Converter
Convert between km/h, mph, m/s, knots, and feet per second.
Time Converter
Convert between seconds, minutes, hours, days, weeks, months, and years.
Guides & explainers
- Unit Conversion GuideConvert units carefully by checking direction, precision, and the real-world context.
- Common Length ConversionsThe conversion factors worth memorising, and mental-math shortcuts for the rest.
- Fahrenheit vs. CelsiusThe exact formula, and the quick approximation that gets you within 2°.
- Litres vs. GallonsOne litre, two different gallons — know which one you are dealing with.
- MPH vs. KM/HMultiply by 1.6 or divide by 1.6 — and two shortcuts that are close enough.
- Metric vs. ImperialWhich countries use which, and the minimum set of conversions for travellers and readers.
- Length Unit Converter GuideEvery common metric and imperial length unit, the exact conversion factors, and the precision rules that keep you out of trouble.
- Weight Unit Converter GuideMass vs weight, the metric–imperial bridge, and the three ton definitions you need to keep straight.
- Temperature Scale GuideWhy temperature is the one "unit" family that breaks the multiply-by-a-factor rule — and the anchors that make every conversion easy.
- Area Unit Converter GuideWhy 1 m² is not 100 cm² — and every other squaring trap that costs people money on construction and land deals.
- Volume Unit Converter GuideEvery kitchen and shipping volume unit — and the crucial US vs UK gallon difference that ruins international recipes.
- Speed Unit Converter GuideThe four common speed units, the anchor values worth memorising, and the nautical-mile quirk that defines the knot.
- Time Unit Converter GuideAll the standard time units, and the non-integer ratios (months, years) that make date math messier than it looks.
Related clusters
Frequently asked questions
› Do these support fractional inputs?
Yes. Enter decimals or fractions (as decimals) and convert freely.
› What's the rounding policy?
Results are displayed to 6 significant figures by default — enough precision for everyday use without noise.