Yes, a range hood with a greater CFM is better. However, when purchasing a range hood, you should not seek out a high-end figure such as 600 cubic feet per minute only for the purpose of having a larger number, but rather to determine which would work best for your kitchen range. So, here's a quick calculation to figure out how much CFM your kitchen range needs. Calculate your range hood's anticipated CFM by multiplying the total BTUs of your kitchen range by 100.