Every unit converter, one fast page

Everyday distance, weight and temperature, plus the specialist units engineers and scientists actually need.

80 categories, 929 units, nothing sent to a server

Most-used conversions

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14 converters

The everyday conversions: distance, weight, volume, temperature and the rest.

Common converters, with the number of units and the base unit for each.
Converter	Units	Base unit	Symbols
Length	38	Meter	km, hm, dam, m, dm
Weight and Mass	30	Kilogram	kg, g, mg, µg, ng
Volume	34	Cubic meter	m³, km³, cm³, mm³, dm³
Temperature	8	Kelvin	K, °C, °F, °R, °Ré
Area	22	Square meter	m², km², hm², dam², dm²
Pressure	22	Pascal	Pa, kPa, MPa, hPa, bar
Energy	26	Joule	J, kJ, MJ, GJ, mJ
Power	20	Watt	W, kW, MW, GW, mW
Force	16	Newton	N, kN, MN, mN, µN
Time	20	Second	s, ms, µs, ns, ps
Speed	17	Meter per second	m/s, km/h, mph, ft/s, kn
Angle	12	Degree	°, rad, grad, mrad, ′
Fuel Consumption	10	Kilometer per liter	km/L, m/L, mpg, mpg uk, mi/L
Data Storage	25	Byte	b, B, nibble, kb, kB

Engineering

8 converters

Rotation, density, inertia and the moments used in mechanical design.

Engineering converters, with the number of units and the base unit for each.
Converter	Units	Base unit	Symbols
Angular Velocity	12	Radian per second	rad/s, rad/min, rad/h, rad/d, °/s
Acceleration	13	Meter per second squared	m/s², km/s², cm/s², mm/s², Gal
Angular Acceleration	6	Radian per second squared	rad/s², rad/min², rev/s², rev/min², rpm/s
Density	17	Kilogram per cubic meter	kg/m³, g/cm³, g/mL, kg/L, g/L
Specific Volume	8	Cubic meter per kilogram	m³/kg, L/kg, cm³/g, mL/g, ft³/lb
Moment of Inertia	8	Kilogram square meter	kg·m², kg·cm², g·cm², g·mm², lb·ft²
Moment of Force	12	Newton meter	N·m, kN·m, mN·m, µN·m, dyn·cm
Torque	11	Newton meter	N·m, N·cm, N·mm, kN·m, kgf·m

Heat

10 converters

Thermal properties, from conductivity and heat capacity to expansion coefficients.

Heat converters, with the number of units and the base unit for each.
Converter	Units	Base unit	Symbols
Fuel Efficiency by Mass	9	Joule per kilogram	J/kg, kJ/kg, MJ/kg, cal/g, kcal/kg
Fuel Efficiency by Volume	9	Joule per cubic meter	J/m³, kJ/m³, MJ/m³, J/L, kcal/m³
Temperature Interval	7	Kelvin	K, °C, °F, °R, °Ré
Thermal Expansion	8	Per kelvin	1/K, 1/°C, 1/°F, 1/°R, µm/(m·K)
Thermal Resistance	6	Kelvin per watt	K/W, °C/W, K/kW, K/mW, °F·h/BTU
Thermal Conductivity	8	Watt per meter per kelvin	W/(m·K), W/(cm·°C), kW/(m·K), mW/(m·K), cal/(s·cm·°C)
Specific Heat Capacity	7	Joule per kilogram per kelvin	J/(kg·K), J/(g·°C), kJ/(kg·K), cal/(g·°C), kcal/(kg·°C)
Heat Density	7	Joule per square meter	J/m², kJ/m², MJ/m², cal/cm², Ly
Heat Flux Density	7	Watt per square meter	W/m², kW/m², W/cm², cal/(s·cm²), kcal/(h·m²)
Heat Transfer Coefficient	5	Watt per square meter per kelvin	W/(m²·K), kW/(m²·K), kcal/(h·m²·°C), BTU/(h·ft²·°F), cal/(s·cm²·°C)

Fluids

10 converters

Flow, viscosity, concentration and the transport quantities of process engineering.

Fluids converters, with the number of units and the base unit for each.
Converter	Units	Base unit	Symbols
Flow Rate	19	Cubic meter per second	m³/s, m³/min, m³/h, m³/d, L/s
Mass Flow Rate	12	Kilogram per second	kg/s, kg/min, kg/h, g/s, g/min
Molar Flow Rate	7	Mole per second	mol/s, mol/min, mol/h, mmol/s, µmol/s
Mass Flux Density	5	Kilogram per second per square meter	kg/(s·m²), kg/(h·m²), g/(s·cm²), lb/(s·ft²), lb/(h·ft²)
Molar Concentration	9	Mole per cubic meter	mol/m³, M, mM, µM, nM
Solution Concentration	13	Kilogram per cubic meter	kg/m³, g/L, mg/L, µg/L, ng/L
Dynamic Viscosity	11	Pascal second	Pa·s, mPa·s, P, cP, µP
Kinematic Viscosity	7	Square meter per second	m²/s, St, cSt, mm²/s, ft²/s
Surface Tension	9	Newton per meter	N/m, mN/m, dyn/cm, erg/cm², erg/mm²
Permeability (Porous Media)	8	Square meter	m², cm², D, mD, µD

Light

5 converters

Photometry and image resolution: luminance, illuminance, DPI and wavelength.

Light converters, with the number of units and the base unit for each.
Converter	Units	Base unit	Symbols
Luminance	11	Candela per square meter	cd/m², nt, sb, cd/ft², cd/in²
Luminous Intensity	8	Candela	cd, mcd, kcd, cp, HK
Illuminance	9	Lux	lx, klx, mlx, lm/m², lm/cm²
Digital Image Resolution	10	Dot per meter	dot/m, dot/mm, dot/cm, DPI, PPI
Frequency ↔ Wavelength	12	Hertz	Hz, kHz, MHz, GHz, THz

Electricity

15 converters

Charge, current, potential, resistance and the reactive component units.

Electricity converters, with the number of units and the base unit for each.
Converter	Units	Base unit	Symbols
Electric Charge	12	Coulomb	C, kC, mC, µC, nC
Linear Charge Density	6	Coulomb per meter	C/m, C/cm, C/in, µC/m, abC/m
Surface Charge Density	6	Coulomb per square meter	C/m², C/cm², C/in², µC/m², abC/m²
Volume Charge Density	6	Coulomb per cubic meter	C/m³, C/cm³, C/in³, µC/m³, abC/m³
Electric Current	9	Ampere	A, kA, mA, µA, nA
Linear Current Density	6	Ampere per meter	A/m, A/cm, A/mm, A/in, kA/m
Surface Current Density	6	Ampere per square meter	A/m², A/cm², A/mm², A/in², kA/m²
Electric Field Strength	9	Volt per meter	V/m, kV/m, V/cm, kV/cm, V/mm
Electric Potential	9	Volt	V, kV, MV, mV, µV
Electric Resistance	9	Ohm	Ω, kΩ, MΩ, GΩ, mΩ
Electric Resistivity	8	Ohm meter	Ω·m, Ω·cm, Ω·in, µΩ·cm, µΩ·m
Electric Conductance	9	Siemens	S, kS, mS, µS, ℧
Electric Conductivity	8	Siemens per meter	S/m, S/cm, mS/cm, µS/cm, mS/m
Electrostatic Capacitance	9	Farad	F, mF, µF, nF, pF
Inductance	9	Henry	H, mH, µH, nH, pH

Magnetism

4 converters

Field strength, flux and flux density in SI and CGS forms.

Magnetism converters, with the number of units and the base unit for each.
Converter	Units	Base unit	Symbols
Magnetomotive Force	5	Ampere-turn	At, kAt, mAt, Gb, abAt
Magnetic Field Strength	7	Ampere per meter	A/m, kA/m, A/cm, A/mm, Oe
Magnetic Flux	8	Weber	Wb, mWb, µWb, Mx, kMx
Magnetic Flux Density	10	Tesla	T, mT, µT, nT, G

Radiology

4 converters

Absorbed dose, dose equivalent, activity and exposure.

Radiology converters, with the number of units and the base unit for each.
Converter	Units	Base unit	Symbols
Radiation Absorbed Dose	8	Gray	Gy, mGy, µGy, kGy, rad
Radiation Dose Equivalent	7	Sievert	Sv, mSv, µSv, nSv, rem
Radiation Activity	13	Becquerel	Bq, kBq, MBq, GBq, TBq
Radiation Exposure	7	Coulomb per kilogram	C/kg, mC/kg, µC/kg, R, mR

Other

10 converters

Data rates, typography, pace, sound levels, prefixes and number bases.

Other converters, with the number of units and the base unit for each.
Converter	Units	Base unit	Symbols
Data Transfer Rate	16	Bit per second	bps, kbps, Mbps, Gbps, Tbps
Cooking Volume	19	Milliliter	mL, L, dL, tsp, tbsp
Volume (Dry)	12	Liter	L, m³, mL, pt dry, qt dry
Volume (Lumber)	10	Cubic meter	m³, fbm, ft³, in³, cord
Metric Prefixes	25	None (×1)	Q, R, Y, Z, E
Frequency	13	Hertz	Hz, kHz, MHz, GHz, THz
Sound Level	4	Decibel	dB, B, Np, dNp
Typography	11	Point (PostScript)	pt, pc, in, mm, cm
Pace	9	Second per meter	min/km, min/mi, s/m, s/km, min/100m
Number Base	14	Decimal	bin, oct, dec, hex, b3

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.

Every unit converter, one fast page

Most-used conversions

Start here

Engineering

Heat

Fluids

Light

Electricity

Magnetism

Radiology

Other

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Common questions