CFM, or cubic feet per minute, measures the volume of air that the leaf blower can move, whereas MPH, miles per hour, measures the speed at which the air moves. It’s important to look at both numbers because they work together. However, a higher airspeed does nothing without a large push power—the volume of air coming out every minute (CFM)—and therefore, large differences in CFM between models can often make a bigger difference in how quickly you can complete a job. Biermeier compares leaf blowers to snow plows, comparing CFM to “volume of pushing power or the size of the snowplow's blade“ and MPH to “the speed of the vehicle pushing the plow.” Larger blades move more snow, whereas faster speeds throw the snow a greater distance. In other words, a higher CFM will reach and move more leaves at a time, whereas a higher MPH will blow the leaves a greater distance. Biermeier advises that you prioritize CFM or MPH based on your particular needs, stating “if you need to move a small amount of leaves over a long distance, aim for higher MPH. If you need to move a lot of leaves a short distance, higher CFM is the way to go.”