Conversion Factors for Some Common Sl Units

An asterisk (*) denotes an exact relationship. Length 1 in : 25.4 mm

1 ft : 0.304 8 m 1 Yd : 0.914 4 m 1 mile : 1.6093km

* I A (angstrom) : IO-”’m

* I h : 3.6 ks *1 day : 86.4 ks

Time * I min : 6 0 s

I year : 31.5 Ms Area I in.’ : 645.16 nun’

1 ft’ : 0.092903m’ I yd2 : 0.83613 m’ I mile’ : 2.590 km’ I acre : 4046.9 m’

Volme 1 in.’ : 16.387 cm’ 1 ftJ : 0.028 32 m’ I yd’ : 0.764 53 m’ 1 UK gal : 4546.1 cm’ 1 US gal : 3185.4 cm’

Mass I 02 : 28.352 g * I lb : 0.453 592 37 kg 1 cwt : 50.802 3 kg I ton : 1016.06 kg

Force 1 Pdl : 0.138 26N 1 Ibf : 4.4482N

‘1 kgf : 9.806 65 N I tonf : 9.9640 kN

*1 dyn : 1W’N Temperature difference * I deg F (deg R) : 5/9 deg C (deg K) Energy (work, heat) I ft Ibf : 1.355 8 J

*1 cal (international table) : 4.1868 J * I erg : W ’ J

* I kWh : 3.6 MJ

1 ft pdl : 0.042 14 J

1 Btu : 1.055 06 kJ 1 hp h : 2.684 5 MJ

1 therm : 105.51 MJ I thermie : 4.185 5 MJ I Btu/ft’ : 37.259 kl/m’ Caloriftc value (volumetric)

760

Mass flow

Mass per unit area

Density

Pressure

Power (heat flow)

Moment of inertia Moment um Angular momentum Viscosity, dynamic

Viscosity, kinematic

Surface energy (surface tension)

Mass flux density Heat flux density

Heat transfer cocfIicient

Specific enthalpy (latent heat, etc.) Specific heat capacity Thermal conductivity

CONVERSION FACTORS

I ft/s 1 mile/h 1 ft3/s 1 ft’/h 1 UK gal/h I US gal/h 1 Ib/h 1 ton/h I Iblin.’ I Ib/ft’ 1 ton/sq mile 1 Ib/in3 1 Ib/ft’ 1 lb/UK gal I Ib/US gal 1 lbf/in.’ I tonf/in.’ I Ibflft’

* I standard atm * I atm (1 kgf/cm’) * I bar 1 ft water I in. water 1 io. Hg 1 mm Hg ( 1 torr) I hp (British) 1 hp (metric)

* I erg/s I ft lbfls 1 Btu/h I ton of refrigeration I Ib ft* 1 Ib ft/s 1 Ib ft’ls

*1 P (poise) I Ib/R h I Ib/ft s

I ft’lh * I S (stokes)

* I crglcm’ * ( I dyn/cm) 1 Ib/h ft’ 1 Btu/h ft’

*1 kcal/h m’ I Btu/h ft’ OF

1 Btu/lb 1 Btu/lb O F

I Btu/h ft O F

* I kcal/h m “C

751

: 0.3048 mls : 0.44704m/s : 0.028 316 m’/s : 7.865 8 cm3/s : 1.262 8 cm3/s : 1.0515 cm3/s

: 0.126 OOg/s : 0.282 24 kg/s : 703.07 kg/m’ : 4.882 4 kg/m’ : 392.30 kglkm’ : 27.680 g/cm’ : 16.019 kg/m3 : 99.776 kg/m’ : 119.83 kg/rn3 : 6.8948 kN/m’ : 15.444 MN/m’ : 47.880 N/m’ : 101.325 kN/m’ : 98.0665 kN/m’ : 10’ Nlm’ : 2.989 1 kN/m’ : 249.09 N/m’ : 3.386 4 kN/m’ : 133.32 N/m* : 745.70 W : 735.50 W

: 1.355 8 W : 0.293 07 W : 3516.9 W : 0.042 140 kg m’ : 0.138 26 kg m/s : 0.042 140 kg m’/s : 0.1 N slm’ : 0.413 38 mN s/m2 : 1.488 2 N slm’ : ~@‘m’/s : 0.258 06 cm’ls

: (10-’N/m) : 1.356 2 g/s m’ : 3.1546W/m1 : 1.163 Wlm’ : 5.678 3 W/m’ K

: 2.326 kJ/kg : 4.186 8 kJ/kg K : 1.730 7 WImK : 1.163 W/mK

: 10-7w

: 10-3~1mz

Taken from MULLIN, J. W.: 77te Chemical Engineer No. 21 I (Sept. 1967), 176. SI units in chemical engineering.