BEHIND THE NUMBERS

Unit library

Definitions and conversion factors for the units used in Computandum. Factors are relative to each quantity’s base unit.

Base = value × factor + offset. Fahrenheit uses (°F − 32) × 5/9 + 273.15. US mpg uses 235.21458333333333 ÷ mpg. Factors displayed as decimal strings can be rounded where the exact factor is a repeating decimal.

Unit	Symbol	Quantity	Factor to base	Offset
Metres	m	length	1	0
Kilometres	km	length	1000	0
Centimetres	cm	length	0.01	0
Millimetres	mm	length	0.001	0
Inches	in	length	0.0254	0
Feet	ft	length	0.3048	0
Yards	yd	length	0.9144	0
Miles	mi	length	1609.344	0
Square metres	m²	area	1	0
Square feet	ft²	area	0.09290304	0
Hectares	ha	area	10000	0
Acres	ac	area	4046.8564224	0
Cubic metres	m³	volume	1	0
Litres	L	volume	0.001	0
Millilitres	mL	volume	0.000001	0
US liquid gallons	US gal	volume	0.003785411784	0
Cubic feet	ft³	volume	0.028316846592	0
Kilograms	kg	mass	1	0
Grams	g	mass	0.001	0
Pounds	lb	mass	0.45359237	0
Ounces	oz	mass	0.028349523125	0
Seconds	s	time	1	0
Minutes	min	time	60	0
Hours	h	time	3600	0
Days	d	time	86400	0
Kelvin	K	temperature	1	0
Celsius	°C	temperature	1	273.15
Fahrenheit	°F	temperature	0.5555555555555556	255.3722222222222
Metres per second	m/s	velocity	1	0
Kilometres per hour	km/h	velocity	0.2777777777777778	0
Miles per hour	mph	velocity	0.44704	0
Pascals	Pa	pressure	1	0
Kilopascals	kPa	pressure	1000	0
Bars	bar	pressure	100000	0
Pounds per square inch	psi	pressure	6894.757293168	0
Joules	J	energy	1	0
Kilojoules	kJ	energy	1000	0
Kilowatt-hours	kWh	energy	3600000	0
Thermochemical calories	cal	energy	4.184	0
Watts	W	power	1	0
Kilowatts	kW	power	1000	0
Megawatts	MW	power	1000000	0
Bytes	B	data	1	0
Kilobytes (decimal)	kB	data	1000	0
Megabytes (decimal)	MB	data	1000000	0
Kibibytes (binary)	KiB	data	1024	0
Mebibytes (binary)	MiB	data	1048576	0
Bits	bit	data	0.125	0
Litres per 100 km	L/100 km	fuel-economy	1	0
Miles per US gallon	US mpg	fuel-economy	reciprocal: 235.21458333333333	0
nautical miles	nmi	length	1852	0
micrometers	µm	length	0.000001	0
nanometers	nm	length	0.000000001	0
light years	ly	length	9460730472580800	0
parsecs	pc	length	30856775814913673	0
milligrams	mg	mass	0.000001	0
metric tons	t	mass	1000	0
US short tons	US ton	mass	907.18474	0
stones	st	mass	6.35029318	0
carats	ct	mass	0.0002	0
square centimeters	cm²	area	0.0001	0
square inches	in²	area	0.00064516	0
square kilometers	km²	area	1000000	0
square miles	mi²	area	2589988.110336	0
square millimeters	mm²	area	0.000001	0
square yards	yd²	area	0.83612736	0
cubic centimeters	cm³	volume	0.000001	0
cubic inches	in³	volume	0.000016387064	0
cubic yards	yd³	volume	0.764554857984	0
imperial gallons	imp gal	volume	0.00454609	0
US customary cups	US cup	volume	0.0002365882365	0
US liquid pints	US pt	volume	0.000473176473	0
US liquid quarts	US qt	volume	0.000946352946	0
US tablespoons	US tbsp	volume	0.00001478676478125	0
US teaspoons	US tsp	volume	0.00000492892159375	0
feet per second	ft/s	velocity	0.3048	0
kilometers per second	km/s	velocity	1000	0
knots	kn	velocity	0.5144444444444445	0
speed of light	c	velocity	299792458	0
atmospheres	atm	pressure	101325	0
megapascals	MPa	pressure	1000000	0
millibar	mbar	pressure	100	0
Conventional millimetres of mercury	mmHg (0 °C)	pressure	133.322387415	0
Conventional inches of mercury	inHg (0 °C)	pressure	3386.388640341	0
torr	Torr	pressure	133.32236842105263	0
International-table BTU	BTU IT	energy	1055.05585262	0
electronvolts	eV	energy	1.602176634e-19	0
foot pounds	ft·lbf	energy	1.3558179483314004	0
kilocalories	kcal th	energy	4184	0
megajoules	MJ	energy	1000000	0
watt hours	Wh	energy	3600	0
btu per hour	BTU IT/h	power	0.2930710701722222	0
Mechanical horsepower	hp mech	power	745.6998715822702	0
metric horsepower	hp metric	power	735.49875	0
Metric horsepower (PS)	PS	power	735.49875	0
tons of refrigeration	TR	power	3516.852842066667	0
newtons	N	force	1	0
kilonewtons	kN	force	1000	0
dynes	dyn	force	0.00001	0
kilogram force	kgf	force	9.80665	0
pound force	lbf	force	4.4482216152605	0
kips	kip	force	4448.2216152605	0
poundals	pdl	force	0.138254954376	0
US short ton-force	US tonf	force	8896.443230521	0
newton meters	N·m	torque	1	0
kilonewton meters	kN·m	torque	1000	0
newton centimeters	N·cm	torque	0.01	0
kilogram force meters	kgf·m	torque	9.80665	0
pound feet	lbf·ft	torque	1.3558179483314004	0
pound inches	lbf·in	torque	0.1129848290276167	0
ounce inches	ozf·in	torque	0.007061551814226044	0
radians	rad	angle	1	0
degrees	°	angle	0.017453292519943295	0
gradians	gon	angle	0.015707963267948967	0
turns	rev	angle	6.283185307179586	0
arcminutes	′	angle	0.0002908882086657216	0
arcseconds	″	angle	0.00000484813681109536	0
Gigabytes (decimal)	GB	data	1000000000	0
Terabytes (decimal)	TB	data	1000000000000	0
Gibibytes (binary)	GiB	data	1073741824	0
Tebibytes (binary)	TiB	data	1099511627776	0
bps	bit/s	data-rate	1	0
kbps	kbit/s	data-rate	1000	0
mbps	Mbit/s	data-rate	1000000	0
gbps	Gbit/s	data-rate	1000000000	0
bytes per second	B/s	data-rate	8	0
kb per second	kB/s	data-rate	8000	0
mb per second	MB/s	data-rate	8000000	0
gb per second	GB/s	data-rate	8000000000	0
hz	Hz	frequency	1	0
khz	kHz	frequency	1000	0
mhz	MHz	frequency	1000000	0
ghz	GHz	frequency	1000000000	0
rpm	rpm	frequency	0.016666666666666666	0
bpm	bpm	frequency	0.016666666666666666	0
radians per second	rad/s	frequency	0.15915494309189535	0
kg per cubic meter	kg/m³	density	1	0
kg per liter	kg/L	density	1000	0
g per milliliter	g/mL	density	1000	0
g per cubic centimeter	g/cm³	density	1000	0
lb per cubic foot	lb/ft³	density	16.01846337396014	0
lb per gallon	lb/US gal	density	119.8264273168966	0
cubic meters per second	m³/s	flow-rate	1	0
cubic meters per hour	m³/h	flow-rate	0.0002777777777777778	0
liters per second	L/s	flow-rate	0.001	0
liters per minute	L/min	flow-rate	0.000016666666666666667	0
liters per hour	L/h	flow-rate	0.0000002777777777777778	0
cubic feet per second	ft³/s	flow-rate	0.028316846592	0
cubic feet per minute	ft³/min	flow-rate	0.0004719474432	0
us gallons per minute	US gal/min	flow-rate	0.0000630901964	0
uk gallons per minute	imp gal/min	flow-rate	0.00007576816666666667	0
US petroleum barrels per day	bbl/d	flow-rate	0.0000018401307283333333	0
weeks	wk	time	604800	0
milliseconds	ms	time	0.001	0
microseconds	µs	time	0.000001	0
nanoseconds	ns	time	0.000000001	0
meters per second squared	m/s²	acceleration	1	0
centimeters per second squared	cm/s²	acceleration	0.01	0
feet per second squared	ft/s²	acceleration	0.3048	0
g force	g₀	acceleration	9.80665	0
gal	Gal	acceleration	0.01	0
Rankine	°R	temperature	0.5555555555555556	0
kilometers per liter	km/L	fuel-economy	reciprocal: 100	0
miles per liter	mi/L	fuel-economy	reciprocal: 62.13711922373339	0
uk mpg	imp mpg	fuel-economy	reciprocal: 282.48093633182214	0
Amperes	A	current	1	0
Milliamperes	mA	current	0.001	0
Microamperes	µA	current	0.000001	0
Nanoamperes	nA	current	0.000000001	0
Kiloamperes	kA	current	1000	0
Volts	V	voltage	1	0
Millivolts	mV	voltage	0.001	0
Microvolts	µV	voltage	0.000001	0
Kilovolts	kV	voltage	1000	0
Megavolts	MV	voltage	1000000	0
Ohms	Ω	resistance	1	0
Milliohms	mΩ	resistance	0.001	0
Microohms	µΩ	resistance	0.000001	0
Kiloohms	kΩ	resistance	1000	0
Megaohms	MΩ	resistance	1000000	0
Gigaohms	GΩ	resistance	1000000000	0
Siemens	S	conductance	1	0
Millisiemens	mS	conductance	0.001	0
Microsiemens	µS	conductance	0.000001	0
Nanosiemens	nS	conductance	0.000000001	0
Siemens per meter	S/m	conductivity	1	0
Millisiemens per meter	mS/m	conductivity	0.001	0
Microsiemens per meter	µS/m	conductivity	0.000001	0
Siemens per centimeter	S/cm	conductivity	100	0
Millisiemens per centimeter	mS/cm	conductivity	0.1	0
Microsiemens per centimeter	µS/cm	conductivity	0.0001	0
Farads	F	capacitance	1	0
Millifarads	mF	capacitance	0.001	0
Microfarads	µF	capacitance	0.000001	0
Nanofarads	nF	capacitance	0.000000001	0
Picofarads	pF	capacitance	0.000000000001	0
Henries	H	inductance	1	0
Millihenries	mH	inductance	0.001	0
Microhenries	µH	inductance	0.000001	0
Nanohenries	nH	inductance	0.000000001	0
Coulombs	C	electric-charge	1	0
Millicoulombs	mC	electric-charge	0.001	0
Microcoulombs	µC	electric-charge	0.000001	0
Nanocoulombs	nC	electric-charge	0.000000001	0
Ampere hours	Ah	electric-charge	3600	0
Milliampere hours	mAh	electric-charge	3.6	0
Volts per meter	V/m	electric-field	1	0
Volts per centimeter	V/cm	electric-field	100	0
Kilovolts per meter	kV/m	electric-field	1000	0
Kilovolts per centimeter	kV/cm	electric-field	100000	0
Millivolts per meter	mV/m	electric-field	0.001	0
Ohm meters	Ω·m	resistivity	1	0
Ohm centimeters	Ω·cm	resistivity	0.01	0
Microohm meters	µΩ·m	resistivity	0.000001	0
Microohm centimeters	µΩ·cm	resistivity	0.00000001	0
Ohm square millimeters per meter	Ω·mm²/m	resistivity	0.000001	0
Webers	Wb	magnetic-flux	1	0
Milliwebers	mWb	magnetic-flux	0.001	0
Microwebers	µWb	magnetic-flux	0.000001	0
Nanowebers	nWb	magnetic-flux	0.000000001	0
Maxwells	Mx	magnetic-flux	0.00000001	0
Teslas	T	magnetic-flux-density	1	0
Milliteslas	mT	magnetic-flux-density	0.001	0
Microteslas	µT	magnetic-flux-density	0.000001	0
Nanoteslas	nT	magnetic-flux-density	0.000000001	0
Gauss	G	magnetic-flux-density	0.0001	0
Milligauss	mG	magnetic-flux-density	0.0000001	0
Amperes per meter	A/m	magnetic-field-strength	1	0
Kiloamperes per meter	kA/m	magnetic-field-strength	1000	0
Amperes per centimeter	A/cm	magnetic-field-strength	100	0
Oersteds	Oe	magnetic-field-strength	79.57747154594767	0
Pascal seconds	Pa·s	dynamic-viscosity	1	0
Millipascal seconds	mPa·s	dynamic-viscosity	0.001	0
Poise	P	dynamic-viscosity	0.1	0
Centipoise	cP	dynamic-viscosity	0.001	0
Micropascal seconds	µPa·s	dynamic-viscosity	0.000001	0
Square meters per second	m²/s	kinematic-viscosity	1	0
Square millimeters per second	mm²/s	kinematic-viscosity	0.000001	0
Stokes	St	kinematic-viscosity	0.0001	0
Centistokes	cSt	kinematic-viscosity	0.000001	0
Square feet per second	ft²/s	kinematic-viscosity	0.09290304	0
Kilograms per second	kg/s	mass-flow	1	0
Kilograms per hour	kg/h	mass-flow	0.00027777777777777777777777777777777777777777777777778	0
Grams per second	g/s	mass-flow	0.001	0
Grams per minute	g/min	mass-flow	0.000016666666666666666666666666666666666666666666666667	0
Pounds per second	lb/s	mass-flow	0.45359237	0
Pounds per hour	lb/h	mass-flow	0.00012599788055555555555555555555555555555555555555556	0
Grays	Gy	absorbed-dose	1	0
Milligrays	mGy	absorbed-dose	0.001	0
Micrograys	µGy	absorbed-dose	0.000001	0
Rads (absorbed dose)	rad	absorbed-dose	0.01	0
Kilograys	kGy	absorbed-dose	1000	0
Sieverts	Sv	equivalent-dose	1	0
Millisieverts	mSv	equivalent-dose	0.001	0
Microsieverts	µSv	equivalent-dose	0.000001	0
Rems	rem	equivalent-dose	0.01	0
Millirems	mrem	equivalent-dose	0.00001	0
Becquerels	Bq	radioactivity	1	0
Kilobecquerels	kBq	radioactivity	1000	0
Megabecquerels	MBq	radioactivity	1000000	0
Gigabecquerels	GBq	radioactivity	1000000000	0
Curies	Ci	radioactivity	37000000000	0
Millicuries	mCi	radioactivity	37000000	0
Microcuries	µCi	radioactivity	37000	0
Nanocuries	nCi	radioactivity	37	0
Grays per second	Gy/s	absorbed-dose-rate	1	0
Grays per hour	Gy/h	absorbed-dose-rate	0.00027777777777777777777777777777777777777777777777778	0
Milligrays per hour	mGy/h	absorbed-dose-rate	0.00000027777777777777777777777777777777777777777777777778	0
Micrograys per hour	µGy/h	absorbed-dose-rate	0.00000000027777777777777777777777777777777777777777777777778	0
Rads per hour	rad/h	absorbed-dose-rate	0.0000027777777777777777777777777777777777777777777777778	0
Joules per kelvin	J/K	heat-capacity	1	0
Kilojoules per kelvin	kJ/K	heat-capacity	1000	0
Thermochemical calories per kelvin	cal th/K	heat-capacity	4.184	0
Thermochemical kilocalories per kelvin	kcal th/K	heat-capacity	4184	0
International-table BTU per Fahrenheit degree	BTU IT/°F	heat-capacity	1899.100534716	0
Joules per kilogram kelvin	J/(kg·K)	specific-heat-capacity	1	0
Kilojoules per kilogram kelvin	kJ/(kg·K)	specific-heat-capacity	1000	0
Joules per gram kelvin	J/(g·K)	specific-heat-capacity	1000	0
Thermochemical calories per gram Celsius degree	cal th/(g·°C)	specific-heat-capacity	4184	0
International-table BTU per pound Fahrenheit degree	BTU IT/(lb·°F)	specific-heat-capacity	4186.8	0
Watts per meter kelvin	W/(m·K)	thermal-conductivity	1	0
Milliwatts per meter kelvin	mW/(m·K)	thermal-conductivity	0.001	0
Watts per centimeter kelvin	W/(cm·K)	thermal-conductivity	100	0
Thermochemical calories per centimeter second Celsius degree	cal th/(cm·s·°C)	thermal-conductivity	418.4	0
Kelvins per watt	K/W	thermal-resistance	1	0
Kelvins per kilowatt	K/kW	thermal-resistance	0.001	0
Celsius degrees per watt	°C/W	thermal-resistance	1	0
Fahrenheit degrees per watt	°F/W	thermal-resistance	0.55555555555555555555555555555555555555555555555556	0
Square meter kelvins per watt	m²·K/W	thermal-insulance	1	0
Clo	clo	thermal-insulance	0.155	0
Square meters per second	m²/s	thermal-diffusivity	1	0
Square millimeters per second	mm²/s	thermal-diffusivity	0.000001	0
Square centimeters per second	cm²/s	thermal-diffusivity	0.0001	0
Square feet per hour	ft²/h	thermal-diffusivity	0.0000258064	0
Watts per square meter	W/m²	heat-flux	1	0
Kilowatts per square meter	kW/m²	heat-flux	1000	0
Watts per square centimeter	W/cm²	heat-flux	10000	0
Milliwatts per square centimeter	mW/cm²	heat-flux	10	0
Ergs per square centimeter second	erg/(cm²·s)	heat-flux	0.001	0
Newtons per meter	N/m	surface-tension	1	0
Millinewtons per meter	mN/m	surface-tension	0.001	0
Dynes per centimeter	dyn/cm	surface-tension	0.001	0
Newtons per centimeter	N/cm	surface-tension	100	0
Reciprocal meters	m⁻¹	wavenumber	1	0
Reciprocal centimeters	cm⁻¹	wavenumber	100	0
Reciprocal millimeters	mm⁻¹	wavenumber	1000	0
Reciprocal micrometers	µm⁻¹	wavenumber	1000000	0
Joules per kilogram	J/kg	specific-energy	1	0
Kilojoules per kilogram	kJ/kg	specific-energy	1000	0
Megajoules per kilogram	MJ/kg	specific-energy	1000000	0
Joules per gram	J/g	specific-energy	1000	0
Watt hours per kilogram	Wh/kg	specific-energy	3600	0
Kilowatt hours per kilogram	kWh/kg	specific-energy	3600000	0
Joules per cubic meter	J/m³	energy-density	1	0
Kilojoules per cubic meter	kJ/m³	energy-density	1000	0
Megajoules per cubic meter	MJ/m³	energy-density	1000000	0
Joules per liter	J/L	energy-density	1000	0
Watt hours per liter	Wh/L	energy-density	3600000	0
Kilowatt hours per cubic meter	kWh/m³	energy-density	3600000	0
Coulombs per kilogram	C/kg	radiation-exposure	1	0
Millicoulombs per kilogram	mC/kg	radiation-exposure	0.001	0
Microcoulombs per kilogram	µC/kg	radiation-exposure	0.000001	0
Roentgens	R	radiation-exposure	0.000258	0
Milliroentgens	mR	radiation-exposure	0.000000258	0
Picoamperes	pA	current	1e-12	0
Femtoamperes	fA	current	1e-15	0
Nanovolts	nV	voltage	1e-9	0
Picovolts	pV	voltage	1e-12	0
Teraohms	TΩ	resistance	1e12	0
Picosiemens	pS	conductance	1e-12	0
Kilosiemens	kS	conductance	1e3	0
Femtofarads	fF	capacitance	1e-15	0
Picohenries	pH	inductance	1e-12	0
Picocoulombs	pC	electric-charge	1e-12	0
Kilocoulombs	kC	electric-charge	1e3	0
Femtocoulombs	fC	electric-charge	1e-15	0
Picowebers	pWb	magnetic-flux	1e-12	0
Picoteslas	pT	magnetic-flux-density	1e-12	0
Terabecquerels	TBq	radioactivity	1e12	0
Nanograys	nGy	absorbed-dose	1e-9	0
Nanosieverts	nSv	equivalent-dose	1e-9	0
Millinewtons	mN	force	1e-3	0
Micronewtons	µN	force	1e-6	0
Meganewtons	MN	force	1e6	0
Nanonewtons	nN	force	1e-9	0
Piconewtons	pN	force	1e-12	0
Micropascals	µPa	pressure	1e-6	0
Millipascals	mPa	pressure	1e-3	0
Gigapascals	GPa	pressure	1e9	0
Nanojoules	nJ	energy	1e-9	0
Microjoules	µJ	energy	1e-6	0
Millijoules	mJ	energy	1e-3	0
Gigajoules	GJ	energy	1e9	0
Terajoules	TJ	energy	1e12	0
Picojoules	pJ	energy	1e-12	0
Femtojoules	fJ	energy	1e-15	0
Nanowatts	nW	power	1e-9	0
Microwatts	µW	power	1e-6	0
Milliwatts	mW	power	1e-3	0
Gigawatts	GW	power	1e9	0
Terawatts	TW	power	1e12	0
Picowatts	pW	power	1e-12	0
Terahertz	THz	frequency	1e12	0

Sources

NIST: NIST Guide to the SI: conversion factors ↗ · 2026-10-07