| Flow Rate | 1.5 US gallons per minute (approximately 5.7 L/min) | 1.8 US gallons per minute (approximately 6.8 L/min) | GPM describes the maximum water volume delivered per minute under the stated test conditions. |
| EPA WaterSense Relationship | Matches the WaterSense maximum flow rate for qualifying bathroom faucets at 60 psi. | Exceeds the 1.5 GPM WaterSense maximum for qualifying bathroom faucets. | For a bathroom lavatory faucet, choose a model specifically certified to the current WaterSense specification. |
| Typical Best-Fit Location | Bathroom lavatory, guest bathroom, powder room, and other hand-washing sinks. | Kitchen, utility, or workshop sink where faster filling and rinsing may be more important. | Confirm the applicable local plumbing code and product category before selecting the flow rate. |
| Water Used at 5 Minutes per Day | 7.5 gallons per day (approximately 28.4 L/day) | 9.0 gallons per day (approximately 34.1 L/day) | The calculation assumes the faucet runs continuously for five minutes each day. |
| Estimated Annual Water Use | 2,737.5 gallons per year (approximately 10,363 L/year) | 3,285 gallons per year (approximately 12,436 L/year) | Based on 5 minutes of operation per day for 365 days. Actual use depends on habits and sensor settings. |
| Potential Difference in Annual Use | Can save approximately 547.5 gallons per year (approximately 2,073 L/year) compared with 1.8 GPM. | Uses approximately 20% more water than a 1.5 GPM faucet when operated for the same amount of time. | Reducing operating time with an automatic shutoff can produce additional savings at either flow rate. |
| Filling and Rinsing Speed | Lower flow may take about 16.7% longer to deliver the same volume than a 1.8 GPM faucet. | Delivers the same volume about 16.7% faster than a 1.5 GPM faucet. | Choose the higher rate only when the sink’s task requires additional flow and the product is permitted for that application. |
| Smart Features to Check | Hands-free sensor, timed shutoff, temperature memory, adjustable sensor range, and low-battery alert. | Hands-free sensor, timed shutoff, temperature memory, adjustable sensor range, and low-battery alert. | Smart functions do not automatically make a faucet WaterSense-compliant; the maximum flow rate and certification must also meet the applicable requirements. |
| Pressure Consideration | WaterSense faucet flow is evaluated at a specified pressure, commonly 60 psi for the bathroom faucet requirement. | Actual flow may vary with household pressure, aerator design, supply-line restrictions, and shutoff-valve position. | Do not compare advertised flow rates without checking the test pressure and product specifications. |
| Recommended Choice | Best choice for a WaterSense-focused bathroom installation and everyday hand washing. | Consider for a kitchen or utility application when the higher flow is useful and local requirements allow it. | For the best smart faucet, match the flow rate to the sink’s purpose rather than choosing solely by sensor or voice-control features. |
| Important Note | EPA WaterSense labeling applies to specific product categories and certification requirements. A 1.5 GPM flow rate alone does not prove certification, while a 1.8 GPM bathroom faucet does not meet the 1.5 GPM WaterSense maximum. Always verify the current certification, installation category, and local plumbing requirements. |