Construction Calculator - Water and Utility

Liters per Minute Calculator

Calculate liters per minute from a measured volume and elapsed time, with a U.S. gallons-per-minute conversion.

Reviewed: August 26, 2026

Calculate Liters per Minute

For the Liters per Minute Calculator, enter water volume and time. It divides measured liters by elapsed minutes and reports liters per minute, U.S. gallons per minute, and liters per hour.

Construction measuring tools arranged beside a residential building project

Formula used

Average flow rate (L/min) = measured liters ÷ elapsed minutes

Liters per Minute Calculator measurement plan showing Water volume liters, Time minutes

Worked liters per minute example

Liters per Minute Calculator example: 240 L ÷ 30 min = 8 L/min. The converted average is 2.11 U.S. GPM or 480 L/h.

Interpret gallons and flow

Use a longer representative timing interval when possible and retain the original metric measurement before comparing converted values.

System effects the formula omits

Container accuracy, short timing intervals, pulsating pumps, changing head, leakage, and flow that varies during the test affect the average.

Questions specific to this calculation

How long should I time a liters-per-minute test?

Enter liters and elapsed minutes to obtain average liters per minute, U.S. gallons per minute, and liters per hour.