b2KIT

Flow Rate Converter

Convert gallons per minute, liters per second, cubic feet per hour, and other flow rates.

Tested tool guide Tested browser tools Checked August 16, 2026

What Flow Rate Converter does, with a checked example

Flow rates combine volume and time, so this converter translates a rate such as gallons per minute into an equivalent rate such as liters per second or cubic feet per hour. Enter the numeric rate, identify its source unit, and choose the destination unit. The conversion changes the volume unit, the time basis, or both while preserving the same throughput. The frequent trap is treating every gallon as identical: US liquid gallons and Imperial gallons have different volumes, so the selected gallon definition matters.

Worked example

A concrete input and expected output from the current implementation.

Input

60 liters per minute to liters per second

Expected output

1 liter per second

One minute contains 60 seconds. Therefore, 60 liters divided by 60 seconds equals 1 liter per second.

How the result is produced

1

Converting the ratio

Flow rate is treated as volume divided by time. The volume part and time part are converted independently, then recombined. Changing liters per minute to liters per second keeps liters unchanged and replaces the one-minute denominator with 60 seconds. Changing gallons per minute to cubic feet per hour changes both sides of the ratio.

2

Reading equivalent rates

Equivalent rates describe the same throughput over different durations. A per-second value is smaller than the equivalent per-minute value when the volume unit stays the same, because each second covers only one-sixtieth of a minute. Some unit relationships produce nonterminating decimals, so displayed digits should be treated as rounded unless the conversion divides evenly, as in the worked example.

Good uses

  • Compare a pump rated in US gallons per minute with a process requirement written in liters per second before reviewing pressure and head.
  • Translate a building fan's cubic feet per minute rating into cubic meters per hour for a ventilation schedule that uses metric units.
  • Convert a measured plumbing flow, such as liters collected per minute, into GPM so it can be compared with a fixture specification.

Limits and checks

  • Confirm whether gallons means US liquid gallons or Imperial gallons; choosing the wrong gallon definition changes the converted rate.
  • The result is volumetric flow, not mass flow. Converting to kilograms per second requires density and, for gases, clearly stated reference conditions.
  • An equivalent flow rate does not establish pump, pipe, valve, or duct suitability; pressure, velocity, losses, and equipment curves remain separate.

Common questions

Can I convert GPM directly to CFM?

Yes, when GPM is a volumetric gallons-per-minute unit and CFM means cubic feet per minute. Both describe volume per time, so they are dimensionally compatible. Select the intended gallon definition before converting. The number alone does not say whether the flow is liquid or gas, and it does not account for pressure or density.

Does converting a fan or pump rating predict actual delivered flow?

No. It only restates the specified volumetric rate in another unit. Actual delivery can differ because system resistance, pressure, elevation, pipe or duct geometry, control settings, and the equipment's operating curve affect performance. Use the converted figure to align units, then evaluate the relevant engineering data for the system.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.

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