Calculating your CFM

0:00 CFM stands for cubic feet per minute. It measures how much air — in cubic feet — a fan or blower moves in one minute.

0:15 Higher CFM means the hood has more strength to draw out smoke. The right rating is the difference between a smoke-free kitchen and a hood that's overwhelmed.

0:30 Choosing the right CFM depends on a few factors. Start with your stove's BTUs.

0:39 BTU (British thermal unit) measures how much heat your stove makes. The rule of thumb is 1 CFM for every 100 BTUs at maximum output.

0:53 For example, a range with a max output of 60,000 BTUs needs at least 600 CFM. That's your BTU minimum.

1:09 Next, factor in your kitchen size. A hood should cycle all the air in your kitchen about 15 times per hour.

1:24 Find your kitchen's volume: length × width × height. A kitchen 16 ft long, 14 ft wide, with 9 ft ceilings is 2,016 cubic feet.

1:48 Divide 60 minutes by 15 air changes to get 4, then divide your volume by that: 2,016 ÷ 4 = 504 CFM — your kitchen minimum.

2:11 Choose whichever is higher — your BTU minimum or your kitchen minimum. Here, 600 CFM from the BTUs wins.

2:31 Duct length matters too. Add 1 CFM per foot of straight duct, 25 CFM per bend, and 40 CFM for a roof cap.

2:52 So 14 ft of duct, two turns, and a roof cap is 14 + 50 + 40 = 104 CFM. Add it to your total: 600 + 104 = about 704 CFM.

3:23 The last factor is how much heavy cooking you do.

3:32 For everyday cooking — boiling, baking, light sautéing — a hood in the 600–900 CFM range is perfect.

3:42 If you regularly sear steaks, wok stir-fry, deep fry, or make lots of smoke and grease, look at 900–1,200 CFM.

3:57 For outdoor kitchens or high-powered pro ranges, go 1,200 CFM or more to handle the extra smoke and competing airflow.

4:15 Choosing the right CFM isn't about the most powerful hood — it's about matching it to how you cook, for better performance, lower noise, and cleaner air.