What Is a CFM Rating for Range Hoods? How Much CFM You Need

Updated October 2026

A CFM rating tells you how much air a range hood can move: CFM stands for cubic feet per minute, the volume of air the hood's blower pulls out of your kitchen each minute. For most homes, size the hood to your cooktop. Gas cooking needs about 100 CFM for every 10,000 BTU of total burner output. Electric and induction cooking needs about 10 CFM per inch of cooktop width.

A good range hood clears smoke from high-heat cooking, removes grease and steam before they settle on your cabinets, and keeps cooking smells from spreading through the house. A hood can look great and still underperform, so check the CFM rating before you buy, not after. This guide covers the rules of thumb, a few worked examples, and the ducting and make-up air details that decide how well the hood works once it's installed.

What does a CFM rating mean on a range hood?

CFM measures the blower's airflow. A higher rating means a stronger motor that can capture and exhaust smoke, grease and odors faster. The number on the spec sheet is the hood's maximum airflow on its highest speed, and most hoods offer several lower speeds for everyday cooking.

More power has trade-offs. A stronger blower is usually louder, may need a larger duct, and above a certain level may trigger make-up air requirements under your local building code. The goal is enough CFM for how you cook, not the biggest number you can find.

How much CFM do you need? Two rules of thumb

Gas ranges and cooktops: the BTU rule

Add up the BTU rating of every burner on your cooktop, then divide by 100. The result is a good minimum CFM.

• Total burner output of 40,000 BTU: about 400 CFM
• Total burner output of 60,000 BTU: about 600 CFM
• Total burner output of 83,000 BTU: about 830 CFM

Pro-style gas ranges with high-output burners add up quickly, so they usually need more CFM than a standard 30-inch range.

Electric and induction ranges: the width rule

Electric and induction cooktops don't produce combustion byproducts, so you size the hood by cooktop width instead. Allow about 10 CFM per inch:

• 30-inch electric or induction range: about 300 CFM
• 36-inch electric or induction range: about 360 CFM

If you sear, stir-fry or cook with a lot of steam, buy a hood with some extra capacity so it isn't running flat out all the time.

Quick reference

Worked examples

Example 1: A 30-inch induction range on an outside wall

Using the width rule, 30 inches × 10 CFM is about 300 CFM. A 30-inch or 36-inch wall-mount or under-cabinet hood in the 300–400 CFM range covers it comfortably, and a short duct run through the outside wall helps the hood deliver close to its rated airflow.

Example 2: A 36-inch pro-style gas range

Forno's 36-inch Galiano gas range has six sealed burners totaling about 83,000 BTU. By the BTU rule, that calls for roughly 830 CFM. Choose a hood at least 36 inches wide (42 inches gives better capture), plan for the duct size the hood's manual specifies, and ask your building department whether make-up air is required at that airflow.

Example 3: A gas cooktop on a kitchen island

Say the island cooktop is 36 inches wide with burners totaling 60,000 BTU. The BTU rule gives about 600 CFM. Because an island hood has no wall or cabinets to help contain rising smoke, go one size wider (a 42-inch island hood) and choose a model toward the upper end of your CFM range.

Wall, island, under-cabinet or insert: how placement changes sizing

• Width first. Your hood should be at least as wide as your cooking surface. Going one size up (for example, a 36-inch hood over a 30-inch range) catches more of the smoke and steam that drift past the edges.
• Wall-mount (chimney) hoods get help from the wall behind the range, which channels rising air into the hood.
• Island hoods are open on all sides and more exposed to cross-drafts, so size them wider and give them more CFM headroom.
• Under-cabinet hoods fit beneath an upper cabinet and work well for 30-inch and 36-inch ranges with standard output.
• Range hood inserts install inside a custom hood or cabinet enclosure, so you get the blower and filters with a built-in look.

Ducting: the other half of the CFM equation

A hood can only move its rated airflow if the ductwork lets it. Long runs, extra elbows and undersized ducts all reduce the airflow you actually get.

• Use the duct diameter listed in the hood's installation manual and don't reduce it.
• Keep the run as short and straight as you can, and vent to the outdoors, not into an attic or wall cavity.
• Higher-CFM hoods generally need larger ducts, so plan the route before cabinets and ceilings are finished.

Ducted vs. ductless: Recirculating (ductless) hoods filter air through charcoal filters and return it to the kitchen. They're an option when outside venting isn't possible, but they don't remove heat or moisture the way a ducted hood does. ZLINE, for example, says its hoods are designed primarily for ducted use, with select models convertible through a charcoal filter kit. If you need one, see our recirculating kits. ZLINE also recommends professional installation for venting and electrical work, especially on island and built-in models.

Make-up air: when a bigger hood needs help

A powerful hood pushes a lot of air out of your home, and that air has to be replaced from somewhere. Above about 400 CFM, many building codes require a make-up air system that brings fresh air back into the house while the hood runs. Requirements vary by location, so check with your local building department or HVAC contractor before you buy a high-CFM hood.

Is more CFM always better? Noise and everyday use

Not necessarily. Bigger isn't always better, and a home kitchen doesn't need a commercial-strength hood. Many manufacturers list noise levels in sones or decibels for each fan speed. That helps you compare hoods, because most everyday cooking happens on the lower speeds. A hood with a little extra capacity can clear the air on a medium setting instead of running loudly on high.

For a typical 30-inch range, a hood around 300–400 CFM is usually plenty. Pro-style gas ranges, heavy searing and wok cooking are where 600 CFM and up makes sense.

Other features to compare

• Are the baffle or mesh filters dishwasher-safe?
• Does the hood suit your venting plan: ducted outside, or convertible to recirculating?
• Does it use LED lighting?
• How many fan speeds does it have, and are noise levels listed for each?
• Is there a delay-off timer or auto-off function?
• Are chimney extensions available for tall ceilings?
• What does the warranty cover? Terms vary by brand. ZLINE range hoods, for example, carry a 3-year parts-only warranty with a limited lifetime warranty on the motor.

Shop range hoods by brand

Browse ZLINE range hoods (including Satin Stainless Steel, formerly DuraSnow®, and Autograph Edition finishes), Forno range hoods and Thor Kitchen hoods, or see every style in our range hood collection. If you're comparing ZLINE wall styles, read Which ZLINE Wall Range Hood Is Right for You? If you're still choosing the range itself, start with How to Choose the Perfect Stove.

The bottom line

Size gas hoods at about 100 CFM per 10,000 BTU and electric or induction hoods at about 10 CFM per inch of cooktop width. Then make the hood at least as wide as the cooktop, give island hoods extra width and power, and plan the ducting and any make-up air before installation day. If you'd like a second opinion on a specific range and hood pairing, our team is happy to help.