Free unit converters that run in your browser
Convert length, weight, volume, pressure, temperature, data sizes, power, energy and torque units instantly, with the exact formula, a conversion table and worked examples for every pair. Pick a converter below — for example cm to inches, kg to pounds, bar to psi or kcal to kJ. Everything runs in your browser: no upload, no signup, no limits, and it works offline.
Which converters are here?
- Pressure — bar, psi, kPa, MPa, Pa, atm and mmHg, with dedicated pages like bar to psi and psi to kPa. Standard atmospheric pressure is exactly 101,325 Pa, i.e. 1.01325 bar or 14.696 psi (BIPM/NIST).
- Temperature — Celsius, Fahrenheit and Kelvin, with pages like Celsius to Fahrenheit. Water freezes at 0 °C (32 °F, 273.15 K) and boils at 100 °C (212 °F) at sea level.
- Data storage — bytes, KB/MB/GB/TB (decimal) and KiB/MiB/GiB/TiB (binary), with pages like MB to GB. A '1 TB' drive shows as about 931 GiB because makers use decimal but operating systems use binary units.
- Power — watts, kW, MW, PS and hp, with pages like kW to PS. One metric horsepower (PS) is exactly 735.49875 W, so 1 kW = 1.3596 PS.
- Energy — joules, kJ, Wh, kWh, calories, kcal and BTU, with pages like kcal to kJ. One kilocalorie equals exactly 4.184 kJ, which is why food labels show both.
- Torque — newton-metres, pound-feet, pound-inches and kgf·m, with pages like Nm to ft·lb. One newton-metre equals about 0.7376 pound-feet.
- Length — mm, cm, m, km, inches, feet, yards and miles, with pages like cm to inches and km to miles. The inch is defined as exactly 2.54 cm.
- Weight — grams, kg, tonnes, ounces, pounds and stone, with pages like kg to pounds. One pound is exactly 0.45359237 kg.
- Volume — millilitres, litres, US gallons, quarts, cups and fluid ounces, with pages like liters to gallons. A US gallon is 3.785 litres; the UK gallon is larger.
The cards above always show every converter that's currently available.
Why a dedicated page per conversion?
A single all-in-one tool answers "what's the number", but a page for bar to psi also gives you the formula, a reference table and the context — which is what you actually need when you're checking a tyre, a boiler or a recipe. Each page links to the reverse conversion and related units, so you're one click from the value you need next.
Private by default
There is no upload and no server round-trip. The conversion happens on your device, so your values stay with you — and the tool keeps working in airplane mode.