GPM to L/min Volumetric Flow Rate Conversion Chart
| Gallon per minute (US) (gpm) | Liter per minute (L/min) | Reference Benchmark | Formula Step |
|---|---|---|---|
| 0.5 gpm | 1.89 L/min | Residential Undersink Reverse Osmosis Drinking Water Dispenser | 0.5 × 3.785412 = 1.89 L/min |
| 1 gpm | 3.79 L/min | Water-Saving Low-Flow Bathroom Lavatory Faucet Aerator | 1 × 3.785412 = 3.79 L/min |
| 2 gpm | 7.57 L/min | WaterSense Certified Domestic Showerhead Discharge Rate | 2 × 3.785412 = 7.57 L/min |
| 2.5 gpm | 9.46 L/min | Standard Commercial Kitchen Pre-Rinse Spray Valve | 2.5 × 3.785412 = 9.46 L/min |
| 5 gpm | 18.93 L/min | Residential Garden Hose Spray Nozzle Full Flow Output | 5 × 3.785412 = 18.93 L/min |
| 10 gpm | 37.85 L/min | Domestic Tankless Gas Water Heater Peak Demand Rating | 10 × 3.785412 = 37.85 L/min |
| 15 gpm | 56.78 L/min | Commercial Automatic Dishwasher Booster Pump Flow Rate | 15 × 3.785412 = 56.78 L/min |
| 20 gpm | 75.71 L/min | Residential In-Ground Swimming Pool Circulation Pump Flow | 20 × 3.785412 = 75.71 L/min |
| 25 gpm | 94.64 L/min | Commercial Building Hydronic HVAC Heating Loop Primary Flow | 25 × 3.785412 = 94.64 L/min |
| 50 gpm | 189.27 L/min | Automotive High-Pressure Car Wash System Delivery Pump | 50 × 3.785412 = 189.27 L/min |
| 75 gpm | 283.91 L/min | Agricultural Micro-Drip Zone Irrigation Sub-Main Feed | 75 × 3.785412 = 283.91 L/min |
| 100 gpm | 378.54 L/min | Light Industrial Chemical Processing Recirculation Pump | 100 × 3.785412 = 378.54 L/min |
| 250 gpm | 946.35 L/min | Commercial Fire Sprinkler System Zone Standpipe Demand | 250 × 3.785412 = 946.35 L/min |
| 500 gpm | 1892.71 L/min | Municipal Water Supply Booster Station Transfer Pump | 500 × 3.785412 = 1892.71 L/min |
| 1000 gpm | 3785.41 L/min | Municipal Stormwater Drainage Culvert Pumping Station | 1000 × 3.785412 = 3785.41 L/min |
Gallon per minute (US) to Liter per minute Formula & Unit Definitions
The conversion ratio derives directly from the international definition of the US liquid gallon, defined as exactly 231 cubic inches (0.003785411784 m³ or 3.785411784 liters). Because both units share the one-minute time denominator, 1 GPM equals exactly 3.785411784 L/min (~3.785412 L/min). Multiplying any flow rate in gallons per minute by 3.785412 calculates the exact discharge in liters per minute.
Quick Estimation: Quick mental shortcut: To convert GPM to L/min in your head, multiply the GPM by 4 and subtract roughly 5%. For example, 10 GPM × 4 = 40; subtract 5% gives 38 L/min (exact: 37.85 L/min); 5 GPM × 4 = 20; subtract 5% gives 19 L/min (exact: 18.93 L/min).
Gallon per minute — GPM
US Customary Flow- Standard US engineering unit for volumetric liquid flow rate (1 GPM = 231 cubic inches per minute)
- Primary rating metric for American plumbing fixtures, hydronic HVAC pumps, and fire protection systems
- Equal to approximately 3.785412 liters per minute (based on the US liquid gallon)
Liter per minute — L/min
SI Metric Standard- Global metric unit for fluid discharge and ventilation flow rates (1 L/min = 1 dm³/min)
- Standard specification across European and Asian industrial pumps, medical respirators, and dosing lines
- Directly equivalent to 0.06 cubic meters per hour and 0.264172 US gallons per minute
Frequently Asked Questions
Q.How do you convert GPM to liters per minute accurately?
Multiply the flow rate in gallons per minute (US) by 3.785412 (or divide by 0.264172). For example, 10 GPM × 3.785412 = 37.85 L/min.
Q.What is the reverse conversion from liters per minute to GPM?
To convert back, use the Liters per Minute to GPM Converter where 1 L/min equals approximately 0.264172 GPM.
Q.Does this calculation apply to US gallons or Imperial UK gallons?
This tool converts US liquid gallons (3.785412 liters). For Imperial UK gallons (4.54609 liters), multiply by 4.54609 instead.
Q.What is the typical residential water flow rate in GPM and L/min?
Modern water-saving bathroom faucets flow at 1.0 to 1.5 GPM (3.79 to 5.68 L/min), while residential showerheads typically flow at 1.8 to 2.5 GPM (6.81 to 9.46 L/min).