Conversion Factors

This table gives conversion factors to convert various units to their SI equivalents. It will not be very useful for people who prefer to use cgs or English units although it can be used to convert from SI to those systems.

Name	To convert from	to	multiply by	divide by
Acceleration	ft/sec^2	m/s^2	0.3048	3.2810
Area	acre	m^2	4047	2.471E-04
Area	ft^2	m^2	9.294E-02	10.7600
Area	hectare	m^2	1.000E+04	1.000E-04
Area	in^2	m^2	6.452E-04	1550
Density	g/cm^3	kg/m^3	1000	1.000E-03
Density	lbm/ft^3	kg/m^3	16.02	6.243E-02
Density	lbm/in^3	kg/m^3	2.767E+04	3.614E-05
Density	lb*s^2/in^4	kg/m^3	1.069E+07	9.357E-08
Density	slug/ft^3	kg/m^3	515.40	1.940E-03
Energy	BTU	J	1055	9.478E-04
Energy	cal	J	4.1859	0.2389
Energy	erg	J	1.000E-07	1.000E+07
Energy	ev	J	1.602E-19	6.242E+18
Energy	ft*lbf	J	1.3557	0.7376
Energy	kiloton TNT	J	4.187E+12	2.388E-13
Energy	kW*hr	J	3.600E+06	2.778E-07
Energy	megaton TNT	J	4.187E+15	2.388E-16
Force	dyne	N	1.000E-05	1.000E+05
Force	lbf	N	4.4484	0.2248
Force	ozf	N	0.2780	3.5968
Heat capacity	BTU/lbm*°F	J/kg*°C	4188	2.388E-04
Heat transfer coefficient	BTU/hr*ft^2*°F	W/m^2*°C	5.6786	0.1761
Length	AU	m	1.496E+11	6.685E-12
Length	ft	m	0.3048	3.2810
Length	in	m	2.540E-02	39.3700
Length	mile	m	1609	6.214E-04
Length	Nautical mile	m	1853	5.397E-04
Length	parsec	m	3.085E+16	3.241E-17
Mass	amu	kg	1.661E-27	6.022E+26
Mass	lbm	kg	0.4535	2.2050
Mass	lb*s^2/in	kg	1200.00	5.711E-03
Mass	slug	kg	14.59	6.853E-02
Mass flow rate	lbm/hr	kg/s	1.260E-04	7937
Mass flow rate	lbm/sec	kg/s	0.4535	2.2050
Moment of inertia	ft*lb*s^2	kg*m^2	1.3557	0.7376
Moment of inertia	in*lb*s^2	kg*m^2	0.1130	8.8510
Moment of inertia	oz*in*s^2	kg*m^2	7.062E-03	141.60
Power	BTU/hr	W	0.2931	3.4120
Power	hp	W	745.71	1.341E-03
Power	tons of refrigeration	W	3516	2.844E-04
Pressure	bar	Pa	1.000E+05	1.000E-05
Pressure	dyne/cm^2	Pa	0.1000	10.0000
Pressure	in. mercury	Pa	3377	2.961E-04
Pressure	in. water	Pa	248.82	4.019E-03
Pressure	kgf/cm^2	Pa	9.807E+04	1.020E-05
Pressure	lbf/ft^2	Pa	47.89	2.088E-02
Pressure	lbf/in^2	Pa	6897	1.450E-04
Pressure	mbar	Pa	100.00	1.000E-02
Pressure	microns mercury	Pa	0.1333	7.501
Pressure	mm mercury	Pa	133.3	7.501E-03
Pressure	std atm	Pa	1.013E+05	9.869E-06
Specific heat	BTU/lbm*°F	J/kg*°C	4186	2.389E-04
Specific heat	cal/g*°C	J/kg*°C	4186	2.389E-04
Temperature	°F	°C	0.5556	1.8000
Thermal conductivity	BTU/hr*ft*°F	W/m*°C	1.7307	0.5778
Thermal conductivity	BTU*in/hr*ft^2*°F	W/m*°C	0.1442	6.9340
Thermal conductivity	cal/cm*s*°C	W/m*°C	418.60	2.389E-03
Thermal conductivity	cal/ft*hr*°F	W/m*°C	6.867E-03	145.62
Time	day	s	8.640E+04	1.157E-05
Time	sidereal year	s	3.156E+07	3.169E-08
Torque	ft*lbf	N*m	1.3557	0.7376
Torque	in*lbf	N*m	0.1130	8.8504
Torque	in*ozf	N*m	7.062E-03	141.61
Velocity	ft/min	m/s	5.079E-03	196.90
Velocity	ft/s	m/s	0.3048	3.2810
Velocity	km/hr	m/s	0.2778	3.6000
Velocity	miles/hr	m/s	0.4470	2.2370
Viscosity - absolute	centipose	N*s/m^2	1.000E-03	1000
Viscosity - absolute	g/cm*s	N*s/m^2	0.1000	10
Viscosity - absolute	lbf/ft^2*s	N*s/m^2	47.87	2.089E-02
Viscosity - absolute	lbm/ft*s	N*s/m^2	1.4881	0.6720
Viscosity - kinematic	centistoke	m^2/s	1.000E-06	1.000E+06
Viscosity - kinematic	ft^2/sec	m^2/s	9.294E-02	10.7600
Volume	ft^3	m^3	2.831E-02	35.3200
Volume	in^3	m^3	1.639E-05	6.102E+04
Volume	liters	m^3	1.000E-03	1000
Volume	U.S. gallons	m^3	3.785E-03	264.20
Volume flow rate	ft^3/min	m^3/s	4.719E-04	2119
Volume flow rate	U.S. gallons/min	m^3/s	6.309E-05	1.585E+04