General tools
Unit converter
Convert length, weight, temperature, volume, area, speed, and digital storage. Pick a category, type a value, and choose units - the result updates as you type. Everything runs in your browser - nothing is uploaded.
How it works
Pick a category - length, weight, temperature, volume, area, speed, or digital storage - then type a value and choose the units to convert from and to. The result updates as you type, and the swap button flips the two units when you want the conversion the other way. It covers the everyday conversions people look up most: kilometres to miles, Celsius to Fahrenheit, kilograms to pounds, litres to gallons, square metres to square feet, and megabytes to gigabytes.
Each conversion goes through a single base unit for the category, so the maths is exact rather than a lookup table of rounded pairs. Temperature is handled with its own formulas because the scales do not share a zero point: Celsius, Fahrenheit, and Kelvin are converted through their proper offsets, not a simple multiplier. Everything runs in your browser and nothing is sent to a server.
Example. Choose Length, enter 10, set "from" to kilometre and "to" to mile, and you get 6.21371 miles. Switch to Temperature and 100 Celsius converts to 212 Fahrenheit. Use the swap button to turn a km to miles conversion into miles to km.
FAQ
How do I convert kilometres to miles?
Select the Length category, enter the distance in kilometres, set "from" to kilometre and "to" to mile. One kilometre is about 0.621371 miles, so 10 km is 6.21371 miles. The tool does this instantly and the swap button reverses it.
How is temperature converted?
Temperature scales have different zero points, so they cannot be converted with a single multiplier. Celsius to Fahrenheit is C x 9/5 + 32, and Kelvin is Celsius + 273.15. The converter applies these formulas, so 0 C is 32 F and 273.15 K.
Which units does it support?
Length (mm to nautical miles), weight (mg to stone), temperature (C, F, K), volume (millilitres to US and UK gallons), area (square mm to square miles and acres), speed (m/s, km/h, mph, knots), and digital storage (bits and bytes through both decimal KB/MB/GB and binary KiB/MiB/GiB).
Are the conversions exact?
They use precise standard factors and convert through a base unit, so they are as accurate as the input. The display trims results to a sensible number of significant figures for readability; the underlying calculation is full precision.