Every unit converter, one fast page
Everyday distance, weight and temperature, plus the specialist units engineers and scientists actually need.
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14 everyday convertersThe everyday conversions: distance, weight, volume, temperature and the rest.
Engineering
8 convertersRotation, density, inertia and the moments used in mechanical design.
Heat
10 convertersThermal properties, from conductivity and heat capacity to expansion coefficients.
Fluids
10 convertersFlow, viscosity, concentration and the transport quantities of process engineering.
Light
5 convertersPhotometry and image resolution: luminance, illuminance, DPI and wavelength.
Electricity
15 convertersCharge, current, potential, resistance and the reactive component units.
Magnetism
4 convertersField strength, flux and flux density in SI and CGS forms.
Radiology
4 convertersAbsorbed dose, dose equivalent, activity and exposure.
Other
10 convertersData rates, typography, pace, sound levels, prefixes and number bases.
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Try a unit symbol such as kn, psi or mAh, or a plain word such as pressure. Clearing the box brings all 80 converters back.
Common questions
Do I need to install anything?
No. Everything runs in the browser, so the converter works on any phone, tablet or desktop with no account and no download.
Where do the conversion factors come from?
From the SI definitions and the exact international agreements that sit under them. An inch is defined as exactly 2.54 cm and a pound as exactly 0.45359237 kg, and every derived unit here is built from those exact values rather than typed in by hand.
Can I link straight to a conversion?
Yes. Each converter writes its state into the address bar, so a URL such as /length.html?from=Meter&to=Foot&value=12 reopens exactly that conversion.
Why do results sometimes switch to scientific notation?
Very large and very small numbers are shown as, for example, 1.5e-9 so that the significant digits stay readable. Set a fixed number of decimals if you would rather see a plain figure.