Garden hoses are pretty simple tools, but understanding flow rate will allow you to use a hose more efficiently. Knowing flow rate will help you:
- Limit wasted water
- Spend less time working
- Prevent damage to plants
Both the diameter and length of the hose will affect the flow rate, along with the water pressure of the source (your spigot). Lets discuss what flow rate is, how to calculate it, and why it is important.
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What is Garden Hose Flow Rate?
Garden hose flow rate is the amount of water that moves from the spigot through the end of the hose over time. It is commonly measured in gallons per minute, or GPM, and assumes a free and open-ended hose (not connected to a sprinkler or a nozzle).
Calculating Your Own Garden Hose Flow Rate
You will need to know 3 measurements to calculate the flow rate of your hose. They are:
- Hose length (often measured in feet)
- Hose diameter (often measured in inches)
- Water pressure from the source (measured in pounds per square inch, or PSI)
With these 3 measurements, you can quickly find out your flow rate using an online calculator.
If you do not know these 3 measurements listed above, there is an another way to determine your hose flow rate. To do this, you will need a bucket or container and you will need to know how many gallons of water it holds.
- Connect your hose to a water source.
- Make sure your hose isn’t kinked and is free flowing (not connected to a nozzle or sprinkler)
- Turn the hose on and fill the container
- With a timer, notate how long it takes to fill the container
Once you have the time it takes to fill the container, you can convert this to gallons per minute. For example, if you have a 5 gallon bucket and it takes 1 minute to fill, you know your flow rate is 5 gallons per minute.
If you don’t need to know the exact flow rate, we provide a chart below with some of the most common hose sizes and diameters. We are assuming your water pressure is 40 pounds per square inch (PSI), which is the most common measurement in homes. Keep in mind, water pressure in homes can range from 40 PSI to 80 PSI.
| Length (feet) | Diameter (inches) | Flow Rate (GPM) |
| 25ft | 1/2” | 24 |
| 25ft | 5/8” | 44 |
| 25ft | 3/4” | 72 |
| 50ft | 1/2″ | 12 |
| 50ft | 5/8″ | 22 |
| 50ft | 3/4″ | 36 |
| 100ft | 1/2″ | 6 |
| 100ft | 5/8” | 11 |
| 100ft | 3/4” | 18 |
Standard Garden Hose Flow Rates
While flow rate will vary based on hose length, hose diameter, and source water pressure, the most common flow rate will be between 10 and 25 gallons per minute.
Does Garden Hose Flow Rate Matter?
When using a hose, knowing how much water is coming out is very important. It can be very frustrating to be using a hose and have too little or too much water coming out. While too little water will make the your job take longer than it should, having too much water can potentially cause damage or over watering.
An example would be watering your garden. When you know how much water you want to be applied, you can calculate the exact amount of time to leave your hose on. This will keep you from wasting water or applying not enough water. You can also find hose timers that will shut the hose off for you after a certain amount of time.
Knowing the flow rate ahead of time, will help you decide on which hose you may want to buy. You can then decide if you need a hose with a high flow rate that will quickly deliver a lot of water but will likely be heavier or a hose with a low flow rate that will deliver water more slowly but be lighter.
What Can Affect Flow Rate?
The factors that will affect the flow rate of your garden hose are:
- Hose diameter
- Water pressure
- Hose length
- Leaks in the hose
- Kinks in the hose
Lets take a closer look at each one of these and what you need to know for each factor.
Hose Diameter
The diameter of the hose has a direct correlation to flow rate. The larger the diameter, the higher the flow rate. Most garden hose diameters are one of three sizes listed below. If you have a 25 foot hose for each diameter below and 40 PSI, the flow rates can be quite different.
- 1/2” has a flow rate of 24 gallons per minute
- 5/8” has a flow rate of 44 gallons per minute
- 3/4” has a flow rate of 72 gallons per minute
As you can see, the diameter of a hose will have a big affect on flow rate. If you need more water for your job, you will want a larger diameter hose.
Water Pressure
Water pressure also has a direct correlation to flow rate. The higher the water pressure, the higher the flow rate. The most common water pressure is 40 PSI. Water pressure rates do vary by home though, and can get as high as 80 PSI. If you have a 25 foot hose and all have 5/8″ inch diameter, the flow rates can be quite different.
- 20 PSI has a flow rate of 32 gallons per minute
- 40 PSI has a flow rate of 44 gallons per minute
- 60 PSI has a flow rate of 56 gallons per minute
As you can see, the water pressure will have a large affect on flow rate. If you don’t know your water pressure, you can buy a simple pressure gauge at any local hardware store. Just follow the package directions on how to use the gauge.
Hose Length
The longer the hose, the lower the flow rate you will have. When water has to travel longer distances, the flow rate will always slow down. If you have 5/8″ diameter hoses connected to a source with 40 PSI, here are the flow rates for the three most common lengths.
- 25 foot has a flow rate of 44 gallons per minute
- 50 foot has a flow rate of 22 gallons per minute
- 100 foot has a flow rate of 11 gallons per minute
If you are wanting a higher flow rate, it is always best to use the shortest hose possible. It is always a good idea to measure or walk off the distance between your spigot and where you will use the hose before buying a new hose.
You can always buy an additional hose and connect to it later if you end up needing a longer hose. When you connect two hoses together, the flow rate will only decrease due to the added length. The actual connection will not affect flow rate.
Leaks in the Hose
A leak in your garden hose is a common reason of a decreased flow rate. If the water is being lost due to a leak, it will reduce the amount of water getting to the end of the hose. Leaks can occur in your hose for many reasons, but three common reasons are:
- Punctures
- Kinks
- Prolonged exposure to harsh weather
Since leaks will decrease flow rate and waste water, you will want to try to avoid these and other common hose problems. Always check your hose before using and fix any leaks.
Kinks in the Hose
If your hose becomes kinked, it will most certainly lower the flow rate. Some kinks will only lower the flow rate while others may stop it completely. As with leaks, you should always check the hose prior to use and remove any kinks.
There are many ways to prevent kinking, such as buying a kink resistant hose and properly storing it. Visit our water hose kink guide if you want to learn more tips on how to prevent them. The material that your garden hose is made of can greatly affect kinks. To read more, visit our article comparing rubber vs vinyl garden hoses.