Measurements

Measurements provided for pump and tank capacities depend on the location of the fire department described.

Imperial gallons
Imperial units are used in Canada, the United Kingdom and parts of the British Commonwealth. Canadian fire departments often still refer to pump and tank capacities in imperial gallons, although many have changed over to metric measurements. Officially, Canada has adopted the metric system. The Canadian fire buffing community tends to use imperial measurements.

Pump capacities are referred to in IGPM (Imperial Gallons Per Minute) and tank capacities in IG (Imperial Gallons). Aerial device lengths are expressed in feet. Length/distance measurements are the same in imperial and US.

Most of the pumps on Canadian fire apparatus are American made, so the pump models are identical but simply express their capacities differently.

US gallons
The United States has its own system of fluid measurement, similar to Imperial in that the units have the same names (gallons, pints, ounces). However, the actual sizes, numerically measured, are different.

Pump capacities are referred to in USGPM (United States Gallons Per Minute) and tank capacities in IG (United States Gallons).

Metric system
Most of the world uses the metric system. Articles for metric countries express pump / tank capacities in litres, namely litres per minute (LPM) and simply litres for tanks.

Conversion
Imperial gallons are larger than their US counterparts:


 * 1 Imperial gallon = 4.5 litres
 * 1 US gallon = 3.8 litres

Typical measurements
Standard conversions are often used when referring to pumps. The math may not be exact, but these are the measurements usually used.
 * 1500 USGPM = 1250 IGPM
 * 1250 USGPM = 1050 IGPM
 * 1000 USGPM = 840 IGPM
 * 750 USGPM = 625 IGPM
 * 500 USGPM = 420 IGPM