In this article I’m going to show you how to measure the flow rate of any tap. You can use this video to measure the flow rate of a shower head, bathtub faucet, bathroom sink, kitchen sink, or even if you want to measure the flow rate of a hose.
You could also check out our app Biome, where we have a calculator to help you find the flow rate.
There are three steps to measure the flow rate of any tap. First, grab a container and a stopwatch. Second, open the tap and allow water to flow into your container as you record the time. Third, use the amount of water you collected and time recorded to calculate the flow rate. I’m going to go through this in a bit more detail and at the end of the video, I’ll give you some common flow rates of sinks, showers, bathtubs, and outdoor hoses so you have something to compare to and know if your measurements are on track.
The first step to measuring flow rate is to grab a container and a stopwatch. To properly measure flow rate you’ll want to grab a container that is big enough to hold at least a few cups of water. You’ll also want to make sure you know the volume of the container for example a one and a half quart pot in your kitchen. You’ll also want to use a container that isn’t too big to avoid wasting time and water. You can also use a container that has measurement markings on it. If the only container that you have that’s large enough to do this with doesn’t indicate the size or doesn’t have measurement markings on it that’s okay as long as you have something smaller you can pour the water into and add up the water collected. You’ll also need a timer to record how long it took you to collect water. You can use a clock, a timer on your laptop, a stopwatch, whatever you have available to use while you fill your container. One thing to keep in mind is to make sure you use something that’s easy enough to turn on the water and the stopwatch at the same time.
The next step to measure flow rate is to collect water and record the time. To do this, place your container under the tap you’re trying to measure the flow rate of. At the same time, start the timer and turn on the water as high as it goes. If you’re using a container you know the volume of, fill the container to the top. Then, shut the water off and stop the timer at the same time. If you’re using a container with measurement markings on it, fill to any volume you want. For something like a shower or a bathtub where the water comes out quickly it’s a little bit harder to measure the flow rate. In this case, it might be helpful to first turn on the water and then stick the container into the water and start the timer at the same time. Shut the water or remove the container from the water and stop the timer at the same time.
The third and final step to measure flow rate is to calculate the flow rate. The equation to measure flow rate is volume divided by time and this is usually given in gallons per minute. You probably collected less than a gallon of water and it probably took you less than a minute to do so, so you’ll have to convert units first. Use the guide in the video to help you. Divide volume by minutes and there you have the flow rate.
As a quick recap, to measure the flow rate of any tap grab a container and timer. Open the tap and allow water to flow into your container as you record the time. Last divide the volume you collected by the time you record it to get your flow rate. Check for common flow rates at the end of the video. You could also use Biome to compare your tap to common taps and get recommendations on how to lower its water use.