Flow Rate Converter
Convert between liters/second, GPM, cubic feet/second, cubic meters/hour, and more
Unit Converter
Enter a value and select units to convert
Common Flow Rates Reference
| Source | Metric | Imperial |
|---|---|---|
| Bathroom faucet | ~4-8 L/min | ~1-2 GPM |
| Kitchen faucet | ~6-10 L/min | ~1.5-2.5 GPM |
| Shower head | ~7.5-9.5 L/min | ~2-2.5 GPM |
| Garden hose | ~30-50 L/min | ~8-13 GPM |
| Fire hydrant | ~1,500-6,000 L/min | ~400-1,500 GPM |
| Washing machine | ~15-30 L/min | ~4-8 GPM |
| Swimming pool fill (via hose) | ~40 L/min | ~10 GPM |
| Mississippi River (avg) | ~16,800 m³/s | ~593,000 CFS |
| Niagara Falls | ~2,800 m³/s | ~99,000 CFS |
Frequently Asked Questions
What is the difference between GPM and CFS?
GPM (gallons per minute) and CFS (cubic feet per second) are both US customary flow rate units. GPM is commonly used for plumbing, pumps, and household water systems. CFS is used for larger flows such as rivers, streams, and stormwater drainage. 1 CFS equals approximately 448.83 GPM.
What is the most common flow rate unit in engineering?
In metric countries, cubic meters per hour (m³/h) and liters per second (L/s) are the most common. In the US, gallons per minute (GPM) is standard for plumbing and HVAC, while cubic feet per minute (CFM) is used for air flow. Industrial processes often use cubic meters per second.
How do I calculate water flow rate?
You can measure flow rate by timing how long it takes to fill a known volume. For example, if a faucet fills a 1-liter container in 6 seconds, the flow rate is 1/6 L/s = 0.167 L/s = 10 L/min. For pipe flow, engineers use the formula Q = A x V (flow rate = cross-sectional area x velocity).