Measure your cooktop width first, then the cabinet opening, height clearance, and depth to choose an under-cabinet range hood that fits and captures properly.
An under-cabinet range hood that’s too narrow leaves your kitchen smoky, and one that’s too deep blocks the cabinet door. It’s a frustrating mistake that a few minutes with a tape measure prevents. When you’re ready to shop, our tested roundup of the best 30 inch under cabinet range hoods helps you compare top picks side by side.
What Measurements Do You Need?
You need four numbers before shopping: cooktop width, cabinet opening width, vertical clearance, and cooktop depth. Whirlpool instructs homeowners to measure the cooking surface width first and use that to select the hood width. KitchenAid gives the same first step, then adds the others.
The hood should be at least as wide as the cooking surface, and Whirlpool notes it’s often preferable to go 6 inches wider for better smoke and steam capture. A 30-inch cooktop pairs naturally with a 30-inch hood, but a 36-inch hood captures more.
How to Measure the Cabinet Opening and Cooktop Depth
KitchenAid says to measure the available space between the cabinets above the cooktop so the hood fits the opening. This width, not the hood’s nominal size, tells you what physically fits. Measure between the inside edges of the left and right cabinets.
Depth matters just as much. KitchenAid instructs measuring the cooktop from the back end to the outside edge, excluding the control panel and trim. Whirlpool also recommends measuring cooking surface depth. Under-cabinet hoods typically run 20 to 60 inches wide, with 30 and 36 inches the most standard sizes, per Whirlpool.
One caution: protruding hardware can add width. One installation guide warns that rivets or straps may add up to 5/8 inch to the total hood width, so account for that when fitting a tight cavity.
What Height Should the Hood Sit Above the Cooktop?
Vertical clearance is the most variable measurement because it depends on your model and manufacturer. KitchenAid says installed clearance should be 24 to 36 inches between the bottom of the hood and the cooktop. Whirlpool adds that under-cabinet hoods typically sit 24 to 30 inches above the cooking surface in many cases.
Installation guides vary further: one suggests 28 to 36 inches, another recommends 30 to 36 inches, and a third says 24 to 27 inches for a 9-inch-tall under-cabinet hood. Check your specific model’s manual rather than assuming one universal number.
Ducted or Ductless: How It Changes Your Measurements
Your venting type affects what you plan. Ducted hoods require measuring the duct route, cutting cabinet openings for duct and electrical pass-throughs, and planning the exterior exhaust path. Ductless models use carbon filters and don’t need exterior ducting, so the measurements are simpler.
Whirlpool and KitchenAid both note these steps apply to under-cabinet hoods over standard cooktops. Downdraft hoods are different: they should match the range width exactly and sit behind it, not above it.
| Measurement | What to Measure | Key Sizing Notes |
|---|---|---|
| Cooktop width | Edge to edge of cooking surface | Hood should be equal or up to 6 inches wider |
| Cabinet opening | Inside edge to inside edge between cabinets | Must fit the hood body plus any protruding hardware |
| Vertical clearance | Cooktop surface to bottom of hood | Typically 24 to 36 inches; check your manual |
| Cooktop depth | Back edge to front, excluding trim | Prevents blocking cabinets or the cooktop itself |
Measure twice before you order. If you’re replacing an existing hood, also measure the mounting hole spacing and duct opening, since they rarely line up perfectly between brands. Matching the cooktop width is the priority, but the cabinet cavity and clearance above determine whether the hood truly fits.
References & Sources
- Whirlpool. “Range Hood Dimensions and Sizes.” Explains measuring cooktop width and depth, 6-inch wider rule, 20–60 inch width range, and 24–30 inch clearance.
- KitchenAid. “What Size Range Hood Do I Need?” Details measuring cabinet opening, cooktop depth excluding trim, and 24–36 inch installed clearance.
- AJ Madison Installation Guide. “Under-Cabinet Range Hood Installation.” Covers mounting holes, duct and electrical cutouts, 28–36 inch clearance, and the 5/8-inch hardware allowance.
