Leaf Blower CFM Vs. MPH: Which Is More Important?

Cheaper isn’t always better, especially with regard to power tools. A higher-priced tool usually means better quality overall. And leaf blowers are no exception to this rule.

When deciding on the best leaf blower for your needs, there are many factors to consider. You want to look at things like horsepower, portability, and weight. You also want to look at speed and airflow, better known as MPH and CFM. But what do those letters actually mean, and how do they help determine the quality?

Cubic feet per minute (CFM) measures how much air flows through the leaf blower each minute. The higher the CFM the more air your leaf blower produces. This number determines how big an area can be cleared in any length of time. Miles per hour (MPH) determines the speed of the air flowing through the nozzle. The higher the MPH the faster the debris is moved.

CFM stands for cubic feet per minute. This is a measurement that determines the volume of air blown through the nozzle in one minute. For example, a leaf blower with 349 CFM means that 349 cubic feet of debris are moved in one minute.

But why is that number important? Knowing the CFM allows the buyer to determine how big of an area they can clear in a period of time. The higher the CFM the more air that passes through and the more debris is moved. Generally speaking, the larger the mouth of the nozzle the more air will blow through, making the CFM higher.

Usually, CFM and MPH are determined by the leaf blower’s engine. The larger and more powerful the motor the higher the CFM and MPH will be.

The CFM and MPH ratings are also regulated by the impeller blades. The impeller is like a fan inside the leaf blower that generates the airflow. Both CFM and MPH rely on the following features of the impeller blades: length, speed, and angle of rotation.

If the impeller has a high degree angle, a larger volume of air is produced, which makes the speed more difficult to maintain.

In truth, it depends on what you need out of your leaf blower. Do you want to move a small amount of leaves quickly? Or do you want to move a lot of leaves over a further distance? Each question determines which rating is more important to you.

It makes sense to consider CFM and MPH together when you’re trying to determine the force and strength of your blower. After all, you want an idea of how much debris you can move before you buy it.

When you combine the CFM and MHP ratings, it explains the strength of the blower. A high rating for both CFM and MPH would mean a powerful airflow overall.

However, combining these two ratings doesn’t give an accurate representation. CFM and MPH can end up affecting each other. Here’s why:

We know that it’s difficult to maintain speed (MPH) when large volumes of air (CFM) are produced. Alternately, if the air volume lessens, the air can blow at a higher and more forceful speed.

If a leaf blower has a high CFM, a larger pile of leaves can be moved, though not very far.

If a leaf blower has a high MPH, a smaller pile of leaves will be moved at a further distance.

These are the lightest and arguably the most commonly purchased leaf blowers. They are portable, easy to maneuver and don’t take up too much space. With speeds of over 190 MPH, a good CFM for a handheld blower is 350-600.

Breaking it down even further, handheld leaf blowers come in different models: corded, cordless, and gas-powered. Each of these models also has its own CFM ranges.

· Corded Leaf Blowers: 225 CFM at 60 MPH to 470 CFM at 270 MPH

· Cordless Leaf Blowers: 350 CFM at 120 MPH to 580 CFM at 168 MPH

· Gas-powered Leaf Blowers: Even though the power source is different, their CFM and MPH values are similar to other handheld models. This ensures the blowers remain the lightest weight possible.

Aside from CFM and MPH, there are other factors that play a part in how much work your leaf blower can do.

For every leaf blower, weight is a considerable factor. We know that the engine size helps determine the CFM and MPH ratings. The bigger the engine the more powerful it will be, which means the CFM and MPH are likely to be higher. But the leaf blower will also be heavier.

For gas leaf blowers, you need to take into account the engine’s horsepower, fuel capacity, and displacement or cubic capacity.

For cordless leaf blowers, you have to pay attention to the battery’s lifespan and voltage.

We’ve covered a lot of the basics in terms of a leaf blower’s CFM and MPH rating. But you may still have more questions. Below are some other things people wondered about leaf blowers and their CFM and MPH values.

The nozzle is the key to changing both the CFM and MPH on a leaf blower. If the nozzle is narrower, the MPH will increase because the air has less room to expand. So, it will blow with more force. However, this decreases the CFM.

If the nozzle is more open, the CFM will increase because the air will come out with more volume. However, this decreases the MPH.

Below are the top 5 high CMF leaf blowers of 2021. (Just remember, a higher CFM typically means a lower MPH. You’ll move more leaves over a longer period of time.)

When choosing a leaf blower, you want to carefully consider its volume of airflow (CFM) as well as the speed of the airflow (MPH). Both ratings are important to take note of. But remember, these two ratings shouldn’t be combined as they work together and affect each other.

The faster the speed the smaller volume of air and vice versa. So, a high MPH means moving a small amount of leaves quickly. While a high CFM means moving more leaves over a longer period of time.

Other factors like the design of the impeller blade and the leaf blower’s weight factor into the CFM and MPH values. Each type of leaf blower—handheld, backpack, or walk-behind—has its own set of CFM and MPH ratings.