Conversion Gallon per minute (GPM) is a measure of how fast a pump or other device can move a certain volume of water. GPM is often used in the context of pumping water and can also be referred to as flow rate or head. The term GPM is often confused with CFM, although the two are not interchangeable. Our GPM calculator is compatible with a variety of measurements and can convert from US gallons to liters, CFM to GPM, and more. To use the calculator, enter a number in the first field and select from the other options (Metric system, CFS, and miner’s inches). Then click “Calculate” to view the converted expression.

The GPM formula is a straightforward one. Start by finding the total capacity of your container, then divide the time it takes to fill that container by 60. For example, if it took 10 seconds to fill a one-gallon container, your GPM would be 12 gallons per minute. Then multiply your result by the amount of head pressure you need to push your water through the system.

Another way to find your GPM is to get a bucket and measure how long it takes to fill up completely with water. Then use the capacity of the bucket to determine how many gallons per minute it can hold, and divide that by the number of seconds it took to fill. For instance, if it took 14 seconds to fill a 5 gallon bucket, your GPM would be around 2 gallons per minute. gpm to lpm converter