How many LPM is 1 GPM?

PlumbingHydraulic Fluid Flow

Liters Per Minute (LPM) Flow Calculator

Convert fluid flow rates across metric and imperial units and calculate fluid flow velocity inside plumbing pipes to avoid water hammer erosion.

Plumbing Field StandardsHydraulic Fluid Flow

Engineering formulations calibrated to IPC, UPC & NEC specificationsSub-Zero Cold Climate Tolerances

Quick Summary & Key Answer

To convert Liters Per Minute (LPM) to US Gallons Per Minute (GPM), divide LPM by 3.78541 (or multiply by 0.264172). For example, 10 LPM equals 2.64 GPM. To convert GPM to LPM, multiply GPM by 3.78541.

1 US Gallon = 3.78541 Liters.
Standard showerheads flow at 7.6 to 9.5 LPM (2.0 to 2.5 GPM).
Water velocity in copper pipes should never exceed 8 feet per second.

Interactive Calculator

Adjust inputs for real-time results

Flow Rate Value

Input Flow Unit

Internal Pipe Diameter

Calculated OutputSafe Flow Velocity (<8 fps)

Liters Per Minute

50.00L/min

US Gallons Per Minute: 13.21 GPM
Liters Per Hour: 3,000 L/hr
Cubic Meters Per Hour: 3.00 m³/hr
Fluid Velocity in Selected Pipe: 5.40 ft/s (1.64 m/s)

Note: Plumbing codes recommend keeping cold water pipe velocity below 8.0 ft/s and hot water below 5.0 ft/s to prevent copper erosion corrosion.

Pipe Flow Velocity Standards

High water velocity creates pinhole cavitation erosion in copper pipe elbows.

Frequently Asked Questions

Common questions regarding this calculation and code compliance

1 US Gallon Per Minute equals exactly 3.78541 Liters Per Minute.