CFM vs. MPH for Leaf Blowers
How to Measure Leaf Blower Power
Whether you’re a savvy homeowner or someone responsible for buying professional landscaping equipment, you don’t just want to buy the cheapest leaf blower on the market. You want to invest in a high-quality leaf blower that will provide enough power to get your cleaning jobs done quickly.
That means you’ll be looking at a lot of numbers while shopping for your next leaf blower: horsepower, weight, and of course, airflow (CFM) and speed (MPH).
But what do CFM and MPH mean, and what do these ratings really tell you about the strength of a leaf blower's airflow?
Find out why these are numbers to look for when you're shopping for the best leaf blower for your budget!
What Is Leaf Blower CFM?
For many people, CFM isn’t a familiar measurement. But CFM is short for cubic feet per minute. It’s a measure of volume, or how much air passes through a leaf blower’s nozzle in one minute.
Because CFM measures a quantity of air, it’s a great way of understanding how much material you can move with your leaf blower or how large an area you can clear in a period of time.
The higher the CFM value, the more air your leaf blower will produce. You’ll be able to clear a wider area in a shorter time.
What Is Leaf Blower MPH?
While CFM might be a less familiar concept, MPH is a concept that anyone who’s ever ridden in a car will readily understand. MPH is short for miles per hour, and it’s a measure of speed. When it comes to leaf blower airflow, MPH specifically measures the rate at which air passes through the nozzle.
What leaf blower MPH is helpful for understanding is how quickly and forcefully your leaf blower can clear leaves and other debris away from you. The higher the MPH rating, the faster and more forcefully that material can be pushed away.
In general, the larger and more powerful a leaf blower’s motor or engine, the higher both the blower’s CFM and MPH ratings will be.
These ratings are also influenced by the impeller, which is the fan-like part inside the blower that creates the airflow. CFM and MPH both depend on these qualities of the leaf blower's impeller blades:
- Angle of rotation
The higher the degree angle of the impeller, the more volume of air is produced and harder it is to maintain speed.
What Is A Good CFM for a Leaf Blower?
Often shoppers ask what a good range for leaf blower CFM is, or which is more important, CFM or MPH. The answer, unsurprisingly, is that it depends.
When it comes to calculating the strength of your leaf blower’s airflow, it makes sense to consider CFM and MPH together, or the overall force of a blower. Measuring strength means that you’re trying to measure how much debris you can clear as quickly as possible.
Combined, CFM and MPH ratings explain strength. A leaf blower that has high numbers for both measurements will have a powerful overall airflow.
However, as one rating, they might not always give you the clearest picture of what you need from your leaf blower.
It's because CFM and MPH are related and can affect each other. As the volume or quantity of the air (known as CFM) increases, the more difficult it is to maintain speed or MPH. Similarly, when the volume or amount of air decreases, the easier it is for the airflow to achieve a higher speed and more force as it travels a narrower area.
To create an analogy, imagine water flowing through a large pipe versus a small drinking straw. The water coming through the bigger pipe will flow out in a thicker, heavier stream, and it won't shoot as far. But, the water moving through the straw will flow out in a thin, more forceful stream which means it can go farther.
With a high leaf blower CFM, a user can clear a large pile of leaves but not blow the leaves as far. With a high MPH leaf blower, a user can push a pile of leaves far away, but the pile will be smaller.
Each different type of leaf blower has CFM and MPH values that fall within a typical range.
Those ranges might be surprising, especially for those who weren't aware of how powerful modern electric leaf blowers are.
However, keep in mind that for all that power, each type of leaf blower has its limitations. A corded electric blower, for example, will be limited by the length of its extension cord, while a cordless blower will have limited battery life.
Tips When Considering CFM and MPH
When you buy your next leaf blower, keep in mind that you will notice some variance in CFM and MPH values from what the manufacturer states. This is because manufacturers measure these values at the tip of the nozzle. However, the leaves you’re cleaning all sit a few inches to a few feet away from the nozzle’s tip. As a result, you’re unlikely to actually see leaves blown away from your cordless leaf blower at 250 MPH.
Also, as suggested above, other product specifications also influence how much work you can get done with your leaf blower:
- Weight (all leaf blowers)
- Horsepower (gas leaf blowers)
- Engine displacement in CCs (gas leaf blowers)
- Fuel capacity (gas leaf blowers)
- Battery amp-hours and voltage (cordless leaf blowers)
For assessing the strength of a leaf blower’s airflow, though, CFM and MPH are both important numbers to note. When you consider them together, you become a savvy shopper out to find the best leaf blower for your money.