The CFM you need depends on your stove size and cooking style
CFM stands for cubic feet per minute — the volume of air a range hood pulls out of your kitchen each minute. A hood that moves too little air leaves grease and odor behind. One that moves too much costs more to run and may create drafts that blow out pilot lights or pull conditioned air out of your home.
The standard rule is 100 CFM per linear foot of cooktop. A 30-inch stove needs roughly 300 CFM. A 36-inch stove needs around 360 CFM. A 48-inch commercial-style range needs 400 to 600 CFM depending on how hard you cook.
That baseline assumes normal home cooking — weeknight dinners, occasional high-heat searing. If you cook professionally at home, fry regularly, or have a gas stove with a powerful burner, you may need 50 percent more. If you cook lightly and have good cross-ventilation from windows, you may get by with less.
Key Takeaways
- Most home cooks need 300 to 400 CFM, which corresponds to a 30- to 40-inch cooktop.
- Gas stoves and frequent high-heat cooking push the requirement higher — often 400 to 600 CFM.
- The CFM rating on the box is measured in ideal conditions; real-world performance drops 10 to 30 percent depending on ductwork length and bends.
- Undersizing a hood is more common than oversizing and leaves you with lingering odor and grease buildup on cabinets.
How cooktop size and fuel type affect CFM needs
Electric coil and smooth-top electric stoves produce less heat spread and fewer fumes than gas. A 30-inch electric cooktop works well with 250 to 300 CFM. Gas burners release moisture and combustion byproducts, so the same 30-inch gas cooktop should have 300 to 350 CFM to handle the extra load.
Induction cooktops sit between the two. They heat cookware directly with electromagnetic energy, so they produce less ambient heat and fewer fumes than gas. A 30-inch induction cooktop often works fine at 250 to 300 CFM, similar to electric.
A 36-inch cooktop — common in larger kitchens — typically needs 360 to 400 CFM for electric or induction, and 400 to 450 CFM for gas. A 48-inch professional-style range with six burners can demand 500 to 600 CFM or more if you use all the burners at high heat regularly.
Why the CFM number on the box is not what you actually get
Manufacturers test hoods in a lab with short, straight ductwork and no obstacles. Real kitchens have longer runs, elbows, dampers, and roof or wall penetrations. Each bend in the duct reduces airflow by 10 to 15 percent. A 25-foot duct run with three elbows can cut your actual CFM by 25 to 40 percent.
A hood rated at 400 CFM in the lab may deliver only 280 to 320 CFM in your kitchen. This is why many builders and contractors recommend buying a hood rated 20 to 30 percent higher than your calculated need — to account for real-world losses.
Ductwork diameter also matters. A 6-inch duct is standard but restrictive. An 8-inch duct moves air more freely and reduces the penalty for long runs. If your ductwork is undersized or has many bends, you lose more CFM than if it is straight and wide.
Ducted versus ductless (recirculating) hoods
Ducted hoods push air outside through a vent in the roof or wall. They remove heat, moisture, and odor completely. A ducted hood needs the CFM rating you calculated based on cooktop size.
Ductless or recirculating hoods pull air through a charcoal filter and blow it back into the kitchen. They do not remove heat or moisture — they only trap some grease and odor. Ductless hoods are easier to install (no ductwork) but less effective and require frequent filter changes. If you are choosing a ductless hood, you can use a lower CFM rating because the goal is odor control, not complete air removal. A 150 to 250 CFM ductless hood is often enough for light to moderate cooking.
If you have the option, ducted is the better choice for serious cooking. Ductless works for light use or when ducting is impossible — for example, in a condo where you cannot penetrate the exterior wall.
How cooking habits change your CFM needs
A household that broils, sears, and fries regularly generates more heat and smoke than one that simmers and steams. If you cook this way, add 50 to 100 CFM to your baseline. A 30-inch gas cooktop would normally need 300 CFM, but if you fry or sear often, aim for 350 to 400 CFM.
Conversely, if you cook mostly with the oven, use low to medium heat, and rarely fry, you can go slightly lower than the standard rule suggests. A 30-inch electric cooktop might work fine at 250 CFM instead of 300.
The size of your kitchen also plays a role. A small kitchen with low ceilings concentrates odor and heat faster, so a slightly higher CFM helps. A large, open kitchen with high ceilings disperses odor naturally, so you may get by with less.
Common CFM ranges by cooktop size
| Cooktop Size | Electric/Induction | Gas |
|---|---|---|
| 24 inches | 200–250 CFM | 250–300 CFM |
| 30 inches | 250–300 CFM | 300–350 CFM |
| 36 inches | 300–350 CFM | 400–450 CFM |
| 42 inches | 350–400 CFM | 450–500 CFM |
| 48 inches | 400–500 CFM | 500–600 CFM |
These ranges assume normal home cooking with standard ductwork. If your ductwork is long or has many bends, add 20 to 30 percent. If you cook lightly or have excellent cross-ventilation, you can use the lower end of the range.
What happens if you choose the wrong CFM
An undersized hood leaves grease and odor in your kitchen. You notice it first on cabinet fronts above the stove — a sticky film that builds up over weeks. Cooking smells linger longer. Your kitchen feels hotter after cooking. Over time, grease accumulates on walls and ceilings.
An oversized hood is less common but has its own problems. It can create negative pressure in your kitchen, pulling air down the chimney or gas water heater flue and causing backdrafting — a safety hazard with gas appliances. It also costs more to run and may be noisier. Most people tolerate a slightly oversized hood better than an undersized one.
If you are unsure, lean toward the higher end of the range for your cooktop size. A 30-inch gas stove works better with a 350 CFM hood than a 300 CFM hood, and the extra cost is small.
Frequently Asked Questions
Can I use a range hood with less CFM if I have a window open?
A window helps but does not replace a hood. Open windows create cross-ventilation that removes some odor and heat, but they do not capture grease particles or fumes at the source. You still need a hood sized for your cooktop. A window is a backup, not a substitute.
Is 600 CFM too much for a home kitchen?
Not if your cooktop is large or you cook with high heat regularly. A 48-inch gas range or a household that fries and sears often can use 600 CFM without problems, provided your ductwork is sized to handle it (8-inch duct is better than 6-inch for this). The main downside is cost and noise, not safety.
What CFM do I need for an island cooktop?
Island hoods need 15 to 20 percent more CFM than wall-mounted hoods because they pull air from all sides instead of having a wall to help contain rising heat and smoke. A 30-inch island cooktop should have 350 to 400 CFM instead of 300 CFM.
Does a higher CFM hood make more noise?
Usually yes. A 400 CFM hood is typically louder than a 300 CFM hood. If noise is a concern, look at the decibel rating (measured in sones) in addition to CFM. A well-designed 400 CFM hood can be quieter than a poorly designed 300 CFM hood, so compare the specs rather than assuming higher CFM always means more noise.
Can I install a range hood with lower CFM and upgrade later?
Not easily. Ductwork is usually built into the wall or cabinet during installation. Upgrading to a higher CFM hood later requires new ductwork, which is expensive and disruptive. Choose the right CFM the first time based on your cooktop size and cooking style.