A common question we get is: How many GPM does a house need? The answer varies quite a bit depending on household size, water usage, and the number of fixtures or appliances running simultaneously.
For example, a two-bedroom one-bath house with no garden has relatively lower flow rate needs than a house with three bathrooms and a large garden. It isn’t as easy as saying “you need 10 GPM for a house.” There are several factors to take into account that will help you figure out the best flow rate for your water system.
The first thing to keep in mind is that an average tap, such as your kitchen faucet, will have a flow rate of around 3 GPM max, and that an average shower will use 3-5 GPM.
With that in mind, you can say that a house with one bathroom may only need around 5 GPM so that they don’t experience a noticeable water pressure drop. But if your household size is larger and has more bathrooms, you will want to plan for a higher flow rate.
Usually, you would want to match a flow rate to be able to handle the highest water usage possible in your situation. If you have a house with three showers, you may want to get a pump system with a high enough flow rate to handle all three showers running simultaneously (somewhere around 12-15 GPM).
Some homes have outside faucets supplying drip systems or sprinkler zones. If you have a garden or do any irrigation, your flow rate requirements may need to be even higher, depending on your water needs. If you run sprinklers, you can look up the type of sprinkler heads you have and get a gallons per minute rating for each individual sprinkler head.
Multiply that GPM rating by how many sprinkler heads you have and that would be the GPM you require to run your sprinkler system correctly. For example, if you have 10 sprinkler heads and each one requires 1.5 GPM, you will need a 15 GPM flow rate from your well pump to keep up with your home’s plumbing system requirements. You can do the same calculations with drip lines based on the GPM rating of each emitter.
| 10RPS05 Pump End |
 |
|
| SEE SPECS |
What if your well has a slow refresh rate and only produces 5 GPM, yet your house requires more than that? This can lead to reduced water availability. The best option is to consider stored water. Getting a larger pressure tank or installing a storage tank with an on-demand pressure pump gives you buffer volume.
A storage tank holds gallons of water regardless of your well’s limited flow rate. With this approach, your water supply is driven by the pressure pump connected to the tank, not solely on what’s coming out of the ground.
Pressure pumps often have a good flow rate for the average household, and you can get one big enough that it will handle your home’s water requirements.
And a larger pressure tank will mean that there is more reserve water volume ready to be pushed into the household, and if the pressure tank is big enough that your water needs are finished before the tank is empty, you won’t have to rely on the flow rate coming from the pump as often.
A pressure tank can push water out quicker than it gets put in, but once the tank is empty, the flow rate will be dependent on the deep well pump supplying it. A large pressure tank makes that less of an issue because it can push more water before it becomes reliant on the incoming flow rate alone.
| 1HP Eco-Steady Continuous Pressure Booster Pump |
 |
|
| SEE SPECS |
Whether you are using well water, city water, or something in between, there’s no single number that applies to every house. Your home may only need 5 GPM during normal moments, but spike to 15 GPM during high demand.
That’s why calculating how much water you need based on household size, fixture use, garden irrigation, and actual supply is so important. With the right approach, you can avoid outages, preserve your equipment, and maintain water quality and pressure.
If you still have any questions at all, you can always call RPS Water Pumps and talk to one of our pump specialists who can help you find that right pump for your specific needs. We offer a wide range of residential water pumps. Call us at 855-374-4406.
