 
Unit Conversion Tables
The following tables provide multiplication factors for converting
values of a physical quantity from one unit to another. The tables
are not comprehensive but include many of the units commonly encountered
in water treatment.
Conversion Factors for
Temperature
From 
To 
Formula 
Fahrenheit (ºF) 
Celsius (ºC) 
(ºF32) x 0.556 
Celsius (ºC) 
Fahrenheit (ºF) 
1.8 x ºC + 32 
Conversion Factors for
Units of Area
Unit A 
Unit B 
To Convert from A to B, multiply A by: 
To Convert from B to A, multiply B by: 
cm² 
in² 
0.155 
6.452 
cm² 
ft² 
0.001 08 
929.03 
m² 
ft² 
10.764 
0.0929 
in² 
ft² 
0.006 94 
144 
Conversion Factors for
Units of Concentration
Unit A 
Unit B 
To Convert from A to B, multiply A by: 
To Convert from B to A, multiply B by: 
mg/dL 
ppm 
10 
0.1 
mg/dL 
g/L 
0.01 
100 
mg/L 
% 
0.0001 
10,000 
mg/L 
ppm 
1 
1 
g/L 
% 
0.1 
10 
Conversion Factors for
Units of Flow Rate
Unit A 
Unit B 
To Convert from A to B, multiply A by: 
To Convert from B to A, multiply B by: 
gpm 
L/min 
3.785 
0.2642 
ft³/min 
L/min 
28.32 
0.0353 
ft³/min 
gpm 
7.481 
0.1337 
Conversion Factors for
Units of Length
Unit A 
Unit B 
To Convert from A to B, multiply A by: 
To Convert from B to A, multiply B by: 
cm 
in 
0.3937 
2.54 
cm 
ft 
0.032 81 
30.48 
meters 
ft 
3.281 
0.3048 
Conversion Factors for
Units of Mass
Unit A 
Unit B 
To Convert from A to B, multiply A by: 
To Convert from B to A, multiply B by: 
g 
lb 
0.0022 
453.6 
kg 
lb 
2.205 
0.4536 
Conversion Factors for
Units of Pressure
Unit A 
Unit B 
To Convert from A to B, multiply A by: 
To Convert from B to A, multiply B by: 
psi (lb/in²) 
ft H_{2}O 
2.307 
0.4335 
psi 
kPa 
6.895 
0.145 
Conversion Factors for
Units of Velocity
Unit A 
Unit B 
To Convert from A to B, multiply A by: 
To Convert from B to A, multiply B by: 
ft/min 
cm/sec 
0.508 
1.969 
ft/sec 
cm/sec 
30.48 
0.0328 
ft/min 
gpm/ft² 
7.481 
0.1337 
ft/sec 
gpm/ft² 
448.9 
0.002 23 
cm/sec 
gpm/ft² 
14.73 
0.0679 
Conversion Factors for
Units of Volume
Unit A 
Unit B 
To Convert from A to B, multiply A by: 
To Convert from B to A, multiply B by: 
gal 
L 
3.785 
0.2642 
gal 
ft³ 
0.1337 
7.481 
gal 
M³ 
0.003785 
264.2 
ft³ 
L 
28.32 
0.035 32 
