How this calculator works
Divide transferred mass by elapsed time to obtain mass flow. Volume measurements require multiplying by density at the measurement conditions. This page interprets pounds as avoirdupois mass, not pounds-force, and uses the exact international pound. A gas volume stated at standard conditions must be paired with its standard density; actual flow requires actual density. Dry air, gasoline and water do not share one conversion factor.
Formula
Mass rate = m/t = rho Q. lb/min = (kg/s) times 60/0.45359237. One avoirdupois pound is exactly 0.45359237 kg.
Worked example
Transferring 0.45359237 kg in 60 s gives exactly 1 lb/min. A liquid of density 1000 kg/m3 flowing at 0.001 m3/s has mass flow 1 kg/s, or 132.2773573 lb/min.
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Frequently asked questions
Is pounds per minute a weight rate?
Here it is a mass rate. A force-rate interpretation would require a different calculation involving gravity.
Can I convert CFM directly to lb/min?
Only with fluid density at the stated volume conditions. Convert ft3/min to m3/s, then multiply by density.
Does gasoline have a fixed density?
No. Composition and temperature matter, so enter measured or documented density for the actual product.