gpm, gps
gpm, gps : Customary symbols for gallons per minute (gal/min) and gallons per second (gal/s), traditional units for measuring the flow of liquids. 1 gpm equals about 3.785 41 liters per minute (L/min) if U.S. gallons are meant, or exactly 4.546 09 L/min if British Imperial gallons are meant