Free Online Unit Converter — Length, Weight, Volume & Temperature
Pick a category to convert between metric and imperial units in real time.
A complete set of unit converters covering everyday and professional needs: length (cm, m, km, in, ft, mi), weight (kg, lb, g, oz), temperature (°C, °F, K), volume (L, gal, fl oz, cups) and area (m², ft², acres, hectares, ping). Each converter shows live results, the underlying formula, and a quick-lookup table for the most-searched values.
All conversions happen on your device — your numbers never leave your browser.
Choose a converter
Length Converter
Convert centimeters, meters, kilometers, inches, feet, yards, miles and more — instantly in your browser.
Open converterWeight Converter
Convert grams, kilograms, ounces, pounds, stones and metric tons — instantly in your browser.
Open converterTemperature Converter
Convert Celsius, Fahrenheit, Kelvin and Rankine — instantly in your browser.
Open converterVolume Converter
Convert liters, milliliters, gallons, fluid ounces, cups, pints and quarts — instantly in your browser.
Open converterArea Converter
Convert square meters, square feet, acres, hectares and ping (坪) — instantly in your browser.
Open converterFrequently asked questions
What units can I convert here?
Length (mm, cm, m, km, in, ft, yd, mi, nmi), weight (mg, g, kg, t, oz, lb, st), temperature (°C, °F, K, °R), volume (mL, L, m³, US/UK fl oz, cups, pints, quarts, gallons) and area (mm² up to mi², plus acres, hectares and ping).
How accurate is the conversion?
The underlying ratios are exact where they exist (for example 1 in = 2.54 cm and 1 lb = 0.45359237 kg). Output is rounded only by the decimal-precision setting you pick.
Is my data sent to a server?
No. Every conversion runs locally — nothing is uploaded.
Can I link directly to a specific conversion?
Yes. Each landing page (for example /length/cm-to-inches or /weight/kg-to-lbs) opens with that pair pre-selected, so you can bookmark and share it.
We do not store any of your data.