How to Choose a Range Hood? | Width, CFM & Fit First

Choosing a range hood starts with matching its width to your cooktop, then sizing airflow to your cooking style, and confirming your installation clearances — get those three right, and the rest follows.

A range hood that looks great but fails to capture smoke, steam, and grease is a kitchen appliance that isn’t doing its job. Most buyers focus on style first, but the decisions that actually determine whether a hood works come down to three measurable things: how wide it is, how much air it moves, and where you mount it. Nail those, and you can pick the finish and features that fit your kitchen without sacrificing performance. This guide walks through the sizing, airflow, and installation rules that matter, then points you to models that deliver on all of them — including our tested picks for 30-inch wall-mount range hoods if you are ready to compare specific options.

Width and Capture Area

The hood should be at least as wide as your cooktop, and wider is usually better. A standard 30-inch cooktop works with a 30-inch hood, but a 36-inch hood that extends three inches past the cooking surface on each side captures rising smoke and grease more effectively, especially on the front burners where heat tends to escape forward.

Depth also matters. The hood needs to overhang the cooktop’s front burners while leaving enough headroom and clearance. Under-cabinet hoods have fixed dimensions, while wall-mount and island hoods often allow slightly more flexibility. Measure your cooktop width first, then shop for a hood that matches or exceeds it.

Mounting Height and Clearance

Mounting height directly affects how well the hood captures airborne particles. For an electric cooktop, the typical clearance is 20 to 24 inches between the cooking surface and the bottom of the hood. For gas cooktops, where more heat and combustion byproducts rise, that clearance increases to 24 to 30 inches. Manufacturers’ instructions always override generic rules — some models require specific heights to maintain performance and safety.

Check your ceiling height before buying. Chimney-style and custom hoods may need more vertical space than your kitchen can provide, especially if ductwork routes through the ceiling. Measure from the cooktop to the ceiling and subtract the manufacturer’s minimum clearance; the remaining space must accommodate the hood body and any duct adapter.

Airflow Sizing and Noise

Airflow is measured in cubic feet per minute (CFM). The basic rule: the hood should exchange the kitchen’s air volume at least eight times per hour. For light cooking — simmering, reheating, boiling pasta — 300 to 400 CFM usually suffices. Frequent frying, searing, grilling, or gas cooking pushes that range upward; 400 to 600 CFM or more is common for heavy kitchens.

Higher CFM usually produces more noise. Sound is measured in sones; a hood rated at 3 sones or less at 200 CFM or more is considered quiet enough for most homes. In open-plan kitchens where the hood is audible from the living area, prioritizing a quieter model at your needed airflow is worth the trade-off.

For high-CFM systems over 600 CFM, check whether local code requires make-up air — a separate ventilation system that replaces the air being exhausted. Without it, a powerful hood can depressurize the home, causing backdrafting from gas water heaters or furnaces.

Ducted versus Ductless

Ducted hoods vent air outside through metal ductwork, removing smoke, moisture, and odors completely. They perform better than ductless models, which recirculate air through charcoal filters and release it back into the kitchen. If your kitchen can support a ducted vent path — through the wall, ceiling, or roof — choose ducted. Ductless hoods are a backup for kitchens where ducting is impossible, such as interior islands or rental units, and they require regular charcoal filter replacements to maintain even modest performance.

Washable mesh filters are standard on ducted hoods, while charcoal filters sit behind them in ductless setups. Both need periodic cleaning or replacement, but dishwasher-safe mesh filters make maintenance simpler.

Common Mistakes to Avoid

Buying by style and finish alone is the biggest miss. A narrow hood over a wide cooktop leaves capture gaps. Mounting outside the recommended clearance range reduces efficiency and can create heat-safety issues on gas ranges. Underestimating airflow for gas cooking leads to lingering smoke and grease buildup. And choosing ductless when a ducted path is feasible leaves performance on the table for no good reason.

Plan the ductwork before buying the hood, especially for wall, roof, or exterior vent terminations. Metal ducting is recommended — plastic or flexible materials can restrict airflow and create fire hazards.