Can a gas stove use a hood sized for an electric stove?

No, gas stoves produce more heat and combustion byproducts, so they require higher CFM. A hood sized for electric (typically 100 CFM per 10 inches of cooktop width) is usually too weak for gas. Use the 100 CFM per 10,000 BTU rule instead.

What if my gas stove is wider than the hood?

A hood narrower than the cooktop is not recommended for gas. It will miss rising smoke and grease from the outer burners. Choose a hood at least as wide as the cooktop, ideally 6 inches wider on each side.

Do I need a makeup air system for a high-CFM gas hood?

Hoods rated above 400 CFM can depressurize a home and cause backdrafts from chimneys or water heaters. Many building codes require a makeup air system for hoods over 400 CFM. Check local codes and consult a professional.

How high should a hood be above a gas stove?

The typical clearance is 24 to 30 inches from the burner surface to the hood's bottom. If you mount higher, you must increase the CFM to maintain performance. Always follow the manufacturer's instructions and local codes.

Kitchen Hood Size for Gas Stove: A Step-by-Step Sizing Guide

Stage 1: Measure Your Gas Cooktop Width

The first step in sizing a hood for a gas stove is measuring the cooktop's width. Use a tape measure from the outer edge of the left burner grate to the outer edge of the right burner grate. Standard residential gas cooktops are typically 30, 36, or 48 inches wide, but custom sizes exist, so always measure rather than assume.

Write down this width in inches. This number becomes the baseline for every other sizing decision. A common rule is that the hood should be at least as wide as the cooktop, but for gas cooking, going wider is strongly recommended. A hood that is 6 inches wider than the cooktop on each side (12 inches total) captures rising smoke and grease more effectively, especially when the hood is mounted higher above the flame.

If your gas stove sits against a wall, a standard under-cabinet or wall-mounted hood sized to the cooktop width is usually sufficient. For a gas stove on an island, the hood must be wider—typically 6 inches wider than the cooktop on all sides—because there is no wall to help contain the airflow.

Measure from outer edge of left burner grate to outer edge of right burner grate.
Record the width in inches; do not rely on the stove's model number.
For gas, add 6 inches on each side (12 inches total) to the hood width if possible.

Stage 2: Apply the 100 CFM Rule for Gas

Hood power is measured in cubic feet per minute (CFM), which indicates how much air the fan moves. For gas stoves, the industry guideline is 100 CFM per 10,000 BTUs of total burner output. To find your stove's total BTUs, check the manual or the label on the underside of the cooktop. Sum the BTU ratings of all burners.

For example, a typical 30-inch gas cooktop with four burners might total 40,000 BTUs, which would require a 400 CFM hood. A powerful 36-inch range with a grill or wok burner could total 60,000 BTUs, needing 600 CFM. This calculation ensures the hood can handle the heat and combustion byproducts that gas cooking produces.

If your stove's BTU rating is not easily available, use a conservative estimate: a 30-inch gas cooktop usually needs at least 400 CFM, a 36-inch needs 600 CFM, and a 48-inch pro-style range often needs 900 CFM or more. When in doubt, round up to the next available CFM rating.

Cooktop Width	Typical Total BTUs	Minimum Hood CFM
30 inches	40,000	400
36 inches	60,000	600
48 inches	90,000	900

Stage 3: Adjust for Ductwork Length and Elbows

The CFM rating on the box assumes a short, straight duct run. In reality, every elbow and every foot of duct reduces airflow. A hood rated at 400 CFM may deliver only 300 CFM through a long, winding duct. To compensate, add 10% to the required CFM for each elbow and 1% for each foot of duct beyond the first 10 feet.

For example, if your kitchen layout requires a 20-foot duct run with two 90-degree elbows, start with your base CFM (say 400) and add 10% for each elbow (20%) plus 10% for the extra 10 feet of duct (10%). That brings the requirement to 520 CFM, so you would choose a 550 or 600 CFM hood.

Duct diameter also matters. A 6-inch round duct can handle up to about 400 CFM efficiently; above that, you need an 8-inch or 10-inch duct. If you are installing a high-CFM hood (900+), plan for a larger duct or the hood will be noisy and ineffective. Always consult a professional if you are unsure about your ductwork's capacity.

Stage 4: Factor in Ceiling Height and Mounting Clearance

The hood's mounting height above the gas stove affects both performance and safety. For gas cooktops, the recommended clearance between the burner surface and the bottom of the hood is typically 24 to 30 inches. A higher mount—up to 36 inches—is acceptable but requires a more powerful fan to capture smoke effectively.

If your ceiling is higher than 9 feet, you may need a chimney extension or a custom duct cover. The hood's fan must also work harder to pull air from a greater distance, so add 10% to your CFM calculation for every 12 inches of extra mounting height above the standard 30 inches.

Check your local building code, as many jurisdictions have specific clearance requirements for gas appliances. A hood mounted too low can be a fire hazard; too high and it simply won't capture grease and smoke. Measure your ceiling height and the planned hood location before finalizing the CFM and size.

Stage 5: Verify Size and Fit with a Template

Before purchasing, create a cardboard or paper template of the hood's width and depth and hold it up at the planned mounting height. This lets you visualize how the hood will look and confirm that it does not block cabinets, windows, or traffic paths. For gas stoves, a hood that is too narrow is a common mistake; the template helps you avoid it.

Also check the hood's depth. Most wall-mounted hoods are 18 to 24 inches deep, which should cover the front burners. If your gas stove has a griddle or a front-facing burner, you may need a deeper hood. Measure from the back wall to the front edge of the front burner to ensure the hood will extend far enough.

Finally, confirm that the hood's duct outlet aligns with your existing or planned ductwork. A hood that is the right CFM but has an incompatible duct connection will require costly adapters. If you are replacing an existing hood, measure the current duct location and size to simplify installation.