conversion factors unit shown below are accurate to five significant figures where FPS is the foot-pound-second system.

FPS to SI units 

Physical Quantity	FPS to SI units	Physical Quantity	FPS to SI units
Acceleration	1ft/s2=0.30480m/s2
Angular Velocity	1rev/min=0.10472 rad/s	Mass	1oz=28.350g
Area	1in2=6.4516cm2		1lb=0.45359kg
	1ft2=0.092903m2		1 cwt=58.802kg
	1yd2=0.83613m2		1 ton=1.0161tonne
	1 acre=0.40469ha	Moment of force	1lbf ft=1.3558Nm
Density	1lb/ft3=16.018kg/m3	Plane angle	1°=0.01745rad
Energy	1ft pdl=0.042140J	Power	1ft lbf/s=1.3558Nm
	1ft lbf=1.35582J	Pressure and stress	1in. Hg=33.864mbar
	1k W h=3.6000MJ		1lbf/in2=6.8948kPa
	1therm=0.10551GJ		1tonf/in2=15.444N/mm2
Force	1pdl=0.13826N	Specific heat capacity	1Btu/(lb°F)=4.1868KJ/(kg°C)
	1lbf=4.4482N	Velocity	1ft/s=0.30480m/s
Length	1in=2,5400cm		1mi/h=1.6093km/h
	1ft=0.30480cm	Volume	1in3=16.387cm3
	1yd=0.91440km		1ft3=0.028317m3
	1mi=1.6093km		1yd3=0.76456m3
			1pt=0.568261
			1gal=4.54611

SI to FPS units

Physical Quantity	SI to FPS units	Physical Quantity	SI to FPS units
Acceleration	1m/s2=3.2808ft/s2	Mass	1 g=0.035274`oz
Angular velocity	1rad/s=9.5493rev/min		1 kg=2.2406lb
Area	1cm2=0.15500in2		1 kg=0.019684cwt
	1m2=10.764ft2		1 tonne=0.98421ton
	1m2=1.1960yd2	Moment of force	1Nm=0.73756 lbf ft
	1 ha=2.4711acre	Plane angle	1rad=57.296°
Density	1kg/m3=0.062428lb/ft3	Power	1W=0.73756 ft lbf/s
Energy	1J=23.730ft pdl		1KW=1.3410 hp
	1J=0.73756ft lbf	Pressure and stress	1mbar=0.02953 in.Hg
	1MJ=0.27778 k W h		1kpa=0.14504lbf/in2
	1GJ=9.4781 therm		1N/mm2=0.064749 tonf/in2
Force	1N=7.2330 pdl	Specific heat capacity	1KJ/(kg°C)=0.23885Btu/(lb°F)
	1N=0.22481 lbf	Velocity	1m/s=3.2808ft/s
Length	1cm=0.39370 in		1km/h=0.62137mi/h
	1 m=3.2808ft	Volume	1cm3=0.061024in3
	1 m=1.0936yd		1m3=35.315ft3
	1 km=0.62137mi		1m3=1.3080yd3
			1l=1.7598pt
			1l=0.21997gal