🔄Unit Converter
Pick a category, choose your units, and convert instantly as you type — bidirectional, no page reloads.
Common conversions
Free Unit Converter — Convert Any Measurement Online Instantly
Need to convert units in a hurry? Our free Unit Converter handles them all in one place. Pick a category—length, weight, temperature, volume, area, speed, time, digital storage, and more—choose your units, and the conversion appears instantly as you type. No buttons to press, no page reloads: change either side and the other updates live, and a single tap swaps the direction.
It covers everyday needs and technical ones alike, from kilometres to miles and Celsius to Fahrenheit, to gigabytes to megabytes and pascals to psi. Each category also shows a handy list of common conversions so you can grab the answer you need even faster. Whether you're cooking, studying, travelling, coding, or working on a project, accurate conversions are always a couple of clicks away.
Simply pick a category and enter a value to convert instantly. No sign-up, no downloads, no limits—just fast, accurate results whenever you need them.
About the Unit Converter
Categories supported
Length
km, m, cm, mm, µm, mi, yd, ft, in, nautical mile
Weight / Mass
tonne, kg, g, mg, lb, oz, stone, US ton
Temperature
Celsius, Fahrenheit, Kelvin, Rankine
Volume
L, mL, m³, US gal, qt, pt, fl oz, imp gal, cup, tbsp, tsp
Area
km², m², cm², hectare, mi², acre, yd², ft², in²
Speed
m/s, km/h, mph, ft/s, knot, Mach
Time
year, week, day, hour, minute, second, ms, µs
Digital Storage
bit, byte, KB, MB, GB, TB, PB, Kb, Mb, Gb
Energy
J, kJ, cal, kcal, Wh, kWh, eV, BTU, ft·lb
Pressure
Pa, kPa, MPa, bar, mbar, atm, psi, Torr
Angle
degree, radian, gradian, arcminute, arcsecond, turn
Fuel Economy
L/100 km, km/L, MPG (US), MPG (Imperial)
How conversion works
All linear conversions go via a base unit — for example, length converts through metres. Any value is first converted to the base, then converted to the target. This approach keeps all factor relationships exact and makes it trivial to add new units.
Temperature is the exception: Celsius, Fahrenheit, Kelvin, and Rankine each have an offset, so they use explicit formulas (e.g. °F = (°C × 9/5) + 32) rather than a single scale factor. The base unit for temperature is Celsius.
Fuel economy is also non-linear because L/100 km and MPG are reciprocal scales. The converter applies the correct reciprocal transformation for each direction.
Digital storage uses binary prefixes (IEC): 1 KB = 1024 bytes, 1 MB = 1024 KB, and so on. Bit-rate units (Kb, Mb, Gb) use SI decimal factors (1 Mb = 1,000,000 bits).
Who it's for
Travellers
Convert km to miles, Celsius to Fahrenheit, and litres to gallons when abroad.
Students & researchers
Switch between SI and imperial for physics, chemistry, and engineering problems.
Cooks & bakers
Convert between cups, tablespoons, ml, and grams when following international recipes.
Developers & IT
Convert between bits, bytes, MB, GB, and TB when working with storage or bandwidth.
Privacy
All conversions run entirely in your browser using JavaScript. No values are stored, logged, or sent to a server. Close the tab and everything is gone.
Frequently Asked Questions
How does the unit converter work?
Pick a category, choose the units you want to convert from and to, and type a value. The result appears instantly and updates live as you type — no button required.
Is it free to use?
Completely free. No sign-up, no downloads, no limits. Convert as often as you like.
What can it convert?
Length, weight/mass, temperature, volume, area, speed, time, digital storage, energy, pressure, angle, and fuel economy. More categories may be added over time.
Can I convert both directions?
Yes, it's fully bidirectional. Type a value in either field and the other updates automatically. A swap button also lets you flip the from and to units with one tap.
Does it handle metric and imperial?
Yes. You can freely convert between metric and imperial units within each category — for example kilometres to miles, kilograms to pounds, litres to US gallons, and Celsius to Fahrenheit.
Is temperature converted correctly?
Yes. Temperature uses proper conversion formulas with the correct offsets, not simple multiplication. For example: °F = (°C × 9/5) + 32, and K = °C + 273.15. Rankine is also supported.
How accurate are the results?
Conversions use precise factors through a common base unit, giving results accurate to 6–7 significant figures — suitable for everyday and most technical use.
Are there quick common conversions?
Yes, each category shows a panel of frequently used conversions so you can grab common answers instantly without typing a value.
Is my data stored?
No. Everything runs in your browser and is never stored or sent to a server.
Does it work on mobile?
Yes. The layout is fully responsive. Category tabs wrap, selectors stack on small screens, and there is no horizontal overflow on any device.