CFM is the measure of how much air your range hood moves per minute
CFM stands for cubic feet per minute — it measures the volume of air a range hood pulls out of your kitchen. A higher CFM means the hood removes smoke, steam, and cooking odors faster. The right CFM for your kitchen depends on your stove size, how often you cook, and what you cook.
Most home range hoods fall between 300 and 900 CFM. A small electric stove in an apartment might need only 300 CFM, while a large gas range in a busy kitchen could need 600 CFM or more. Undersizing leaves smoke and steam in your kitchen; oversizing wastes energy and creates unnecessary noise.
Key Takeaways
- A basic rule is to choose 100 CFM for every 10,000 BTU of cooking power your stove produces, though this varies by cooking style and kitchen layout.
- Gas stoves typically need higher CFM than electric stoves because they produce more heat and moisture.
- A range hood ducted outside (vented to exterior) works more efficiently than a recirculating hood that filters and returns air to the kitchen.
- Noise level increases with CFM, so balance ventilation power against how loud you want the hood to be during cooking.
- Your kitchen's layout and ductwork length affect real-world performance, so a hood rated for higher CFM may underperform if ducts are long or poorly installed.
How to calculate CFM based on your stove type
The most common sizing method uses your stove's BTU output. Most home gas ranges produce between 35,000 and 65,000 BTU total. Divide the BTU by 100 to get a starting CFM number. A 50,000 BTU stove would suggest a 500 CFM hood.
Electric stoves produce less heat and moisture, so they typically need less CFM. A standard electric range usually works well with 300 to 400 CFM. If you have a large electric range or cook frequently with high heat, move toward the higher end.
Induction cooktops produce the least heat and steam, so 250 to 350 CFM is often sufficient. However, if you cook with woks, fry foods regularly, or have a very open kitchen layout, add 100 to 150 CFM to any of these numbers.
Ducted hoods versus recirculating hoods and CFM
A ducted hood vents air outside through ductwork. It removes moisture and odors completely from your home. Ducted hoods perform at their rated CFM, so a 500 CFM ducted hood actually moves 500 cubic feet of air per minute out of your kitchen.
A recirculating hood pulls air through a filter and returns it to the kitchen. It removes some odors and grease but not moisture or heat. Recirculating hoods lose 20 to 30 percent of their rated CFM because the filter creates resistance. A 500 CFM recirculating hood may only move 350 to 400 CFM in real use. If you must use a recirculating hood, choose one rated 20 to 30 percent higher than your calculated need.
Ducted installation is more work but performs better. If you are remodeling or building, ducted is the stronger choice. If you rent or cannot modify walls, recirculating is your option, but expect less effective odor and moisture removal.
How ductwork length and bends affect real performance
A range hood's rated CFM assumes ideal conditions — usually a short, straight duct to the outside. In reality, long ducts and elbows create friction that reduces airflow. Every 10 feet of straight ductwork reduces CFM by roughly 10 to 15 percent. Each 90-degree elbow reduces it by another 10 to 15 percent.
If your hood is 20 feet from the exterior wall with two elbows, you might lose 40 to 50 percent of the rated CFM. A 500 CFM hood could perform like a 250 to 300 CFM hood in that setup. When planning your installation, measure the actual duct route and add 20 to 30 percent to your calculated CFM to account for ductwork losses.
Smooth, rigid ductwork performs better than flexible ducting, which has more internal friction. If you have a choice, use rigid metal duct. If you must use flexible duct, keep it as short as possible and avoid coiling or kinking it.
Noise level increases with CFM
Higher CFM hoods move more air, but they also make more noise. CFM and noise are closely linked — a 600 CFM hood is noticeably louder than a 400 CFM hood. Noise is measured in sones; most home hoods range from 3 to 8 sones.
A 3 to 4 sone hood is quiet enough for conversation while cooking. A 6 to 8 sone hood is loud and can be annoying during extended cooking. If noise matters to you, choose a hood with a lower sone rating even if it means slightly less CFM. Many hoods have multiple speed settings, so you can run at lower CFM for everyday cooking and higher CFM only when you need it.
Island and wall-mounted hoods need different CFM
An island hood (mounted above a cooktop in the middle of the kitchen) has to pull air from all directions. It needs 15 to 20 percent more CFM than a wall-mounted hood over the same stove. A wall-mounted hood has a wall behind it to help direct air toward the hood, so it works more efficiently.
If you have an island cooktop, add 100 to 150 CFM to your calculated number. A 50,000 BTU gas range over an island might need 600 CFM instead of 500 CFM for a wall-mounted hood.
Common CFM ranges for different kitchen setups
| Stove Type & Size | Typical CFM Range | Notes |
|---|---|---|
| Small electric range (apartment) | 250–350 CFM | Lower heat output; recirculating hoods work here |
| Standard electric range (30 inches) | 300–400 CFM | Moderate cooking; ducted preferred |
| Large electric range (36+ inches) | 400–500 CFM | Frequent cooking; ducted recommended |
| Small gas range (35,000–40,000 BTU) | 350–450 CFM | Higher heat than electric; ducted |
| Standard gas range (50,000 BTU) | 500–600 CFM | Most common home gas stove |
| Large gas range (60,000+ BTU) | 600–900 CFM | Professional or high-use kitchen |
| Island cooktop (any type) | Add 100–150 CFM | Pulls from all sides; less efficient |
Frequently Asked Questions
Is higher CFM always better?
Higher CFM removes smoke and steam faster, but it also costs more, uses more energy, and creates more noise. Oversizing wastes money and makes your kitchen louder without much real benefit. Match CFM to your stove size and cooking habits — a 600 CFM hood over a small electric range is overkill.
Can I use a range hood with lower CFM than recommended?
An undersized hood will not remove all smoke and steam, especially during heavy cooking or frying. You may notice lingering odors, grease buildup on walls, and moisture problems. It is better to size correctly from the start than to replace a hood later because it does not work well enough.
Does a recirculating hood work as well as a ducted hood?
Recirculating hoods remove some grease and odor but leave moisture and heat in your kitchen. They work best in small kitchens with light cooking. For regular cooking or larger kitchens, a ducted hood performs much better. If you must use recirculating, choose a higher CFM rating to compensate for filter resistance.
What if my kitchen has a very open layout?
Open kitchens lose more air to surrounding spaces, so the hood has to work harder. Add 100 to 150 CFM to your calculated number if your kitchen opens directly into a large living area. A hood rated for a closed kitchen will underperform in an open layout.
How do I know if my ductwork is causing CFM loss?
Measure the distance from your hood to the exterior vent and count the elbows. If the duct is longer than 15 feet or has more than two elbows, you are losing significant CFM. Ask an installer to calculate the actual airflow for your specific ductwork, or add 30 percent to your calculated CFM as a safety margin.