What is a Typical Home Water Flow Rate?

The moment you’re putting a bath bomb in the tub and trying to unwind at the end of a long day is the worst time for your water flow rate to drop. But if you’re in a household of more than four people, or your dishwasher is running while you’re about to bathe, then experiencing limited water flow isn’t just a hypothetical — it’s likely.

But it's not just water flow that can affect your home's plumbing fixtures and appliances. Water pressure is also a factor. We'll help you better understand the difference between the two terms, what a typical home's water flow rate is, and if installing a water filter can have any negative effects.

First, let’s understand the difference between your water flow rate and your water pressure. They might sound like similar terms, and they both have to do with friction, but they differ enormously.

Water flow refers to the amount of water you have flowing through your pipes at any given time. This will depend on how wide your pipes are and the pressure of your water. We break down the math of measuring your water flow rate below.

Water pressure — typically measured in pounds per inch (psi) — is the force that makes your water move through your home's plumbing system. Water pressure is determined by gravity and can be based on several factors, including how high your water source (for example, a water tower) is, the altitude of your home, or the plumbing equipment (including water filtration equipment) you have installed.

The easiest way to illustrate the difference between water flow and water pressure is that water flow refers to the amount of water moving through your pipes, and water pressure refers to how hard or fast that water is flowing.

According to Hustle, having low flow doesn't necessarily mean you have low water pressure. However, low water pressure always causes low flow.

Your water flow rate, also known as your gallons per minute or GPM, is the measurement of how many gallons of water could potentially come out of your kitchen faucet or bathtub per minute.

Your flow rate depends on a mix of factors, but the first thing is your household size. Standard household sizes are 2-4 people. After four people, you’re considered a “large household”. That small difference in verbiage makes all the difference when you’re trying and failing to rinse out your coffee mug in the morning.

But the classification of “large household” doesn’t automatically mean that your flow rate is destined to be lower than others; the thing that hampers your flow rate is the likelihood that many people will be using water within the same house at the same time.

The second factor that affects your water flow rate is the square footage of your home. Determining your flow rate per square foot can actually be broken down using a simple equation. In layman’s terms, this equation determines what your water filter loading capacity will be, your media backwash rate, and will also help you understand if and when you’ll experience pressure drop.

The typical inlet water pressure to a standard size home is usually between 40 to 45 pressure-per-square-inch (psi). For a standard household, it should never exceed 60 psi— that’s why many plumbers automatically set your pressure regulator to 50 psi. But it’s important to remember that no matter how you configure your psi, not all homes are standard. That’s why pressure regulators can be changed between 25 and 75 psi without even breaking a sweat.

So, if the standard home square footage in the United States is 2,322 sq. ft., then it’s reasonable to assume that any home that is above that could potentially experience a diminishing flow rate.