Cooker hoods split into two groups that need completely different measuring. One group hangs on a wall or drops from a ceiling and has no cutout at all. The other slides into a cabinet and has an aperture as unforgiving as an oven's.
Work out which one you are buying first, because the measurements you need are not the same.
Wall-mounted, chimney and island hoods have no cutout
The Bosch DWB and DWK wall-mounted hoods and the DIB island hoods publish product dimensions only. No cutout is listed for them, and that is correct rather than missing data. They mount to a wall or ceiling and there is nothing to cut.
What you measure instead is the wall run, the distance from the hob centreline to each side, and the vertical space between the worktop and the ceiling or the underside of the wall cabinet above. Bosch's 90 cm wall hoods, including the DWB98JQ50B, DWB97BK61T and DWB91PR50A, are all 898 mm wide and 500 mm deep. The island DIB98JQ50 is 898 mm wide and 600 mm deep, which is worth knowing if it is going over a peninsula that people walk past.
Telescopic and canopy hoods do have a cutout, and it is all over the place
Telescopic hoods hide inside a cabinet and pull out to run. That cabinet needs an opening cut for them, and the required opening varies more between models than anything else in the catalogue.
Three Bosch 60 cm telescopic hoods, all sold as 60 cm, all 598 mm wide as products:
- DFT63CA61B: cutout 598 x 300 mm
- DFS067A51B: cutout 524 x 290 mm
- DFT63AC50: cutout 460 x 280 mm
That is a 138 mm difference in required aperture width between the widest and narrowest, on hoods you would put side by side in a comparison and call equivalent. The 90 cm range is no more consistent: the DFT93CA61B needs 898 x 300 mm, the DHI923GSG 850 x 280 mm, the DFT93AC50 760 x 280 mm, and the DFS098K54 and DFS097A51B only 524 x 290 mm.
Canopy hoods behave similarly. The Bosch DHL755BM and DHL755BL are both 730 mm wide and need a 700 x 350 mm opening.
A note on how we handle Fujioh hoods
Fujioh does not publish a separate aperture for its hoods. Where that is the case we show the product footprint as the cutout figure and tag the product so you can see we have done it. The FR-SC2090, FR-MS2390 and FR-CL1890 all show 900 mm, which is the hood width, not a verified cabinet opening.
Treat those as a starting point and check the installation drawing that ships with the unit before anyone cuts anything. We would rather flag the gap than quietly publish an estimate as though it were a manufacturer figure.
Sizing the hood against the hob
The working rule is that the hood should be at least as wide as the hob, and wider is better because cooking vapour does not rise in a neat vertical column.
Run the actual numbers rather than the labels. A 78 cm hob measures about 780 mm across the glass. A Bosch 90 cm hood is 898 mm wide, so it covers that hob with roughly 60 mm of overhang each side. Pair the same 780 mm hob with a 60 cm hood at 598 mm and you are 182 mm short, with the outer burners sitting outside the capture area entirely.
Our 60 cm cooker hoods and 90 cm cooker hoods are split out for exactly this comparison.
Extraction rate is a sizing decision too
Published extraction across the cooker hoods we carry ranges from 260 m3/h at the quiet end to 1200 m3/h at the loud one. A few real figures:
- Fujioh FR-MS2390 and FR-MS2370: 260 m3/h
- Fujioh FR-MT1990: 270 m3/h
- Bosch DFT63CA61B and DFT93CA61B: 310 m3/h
- Bosch DWB97BK61T: 582 m3/h. DWB91PR50A: 602 m3/h
- Teka CNL 6415 BK: 730 m3/h. GFX 72: 750 m3/h. GFI 97350 Integra: 766 m3/h
- Teka DDI 90 downdraft: 1000 m3/h. CC 485 island: 1200 m3/h
Singaporean home cooking, if it involves a wok and high heat, puts out far more grease-laden air than European test conditions assume. If you stir-fry regularly, the 260 to 310 m3/h end of that list is optimistic for an enclosed kitchen. This is one place where over-specifying costs you very little and under-specifying is a daily annoyance.
Height above the hob
Every hood ships with a minimum mounting height in its manual, and it differs between gas and induction because the flame is the constraint. Do not take a number from a blog for this one, including ours. Read the installation instructions for the model you are buying, and if you are pairing a hood with a gas hob, check the hob manual too since it also specifies a minimum clearance to anything above it.
What you can measure now is the space you have: worktop to ceiling, and worktop to the underside of any wall cabinet the hood sits between.
Ducted or recirculating changes the measurement
A ducted hood needs a route to an external vent, and the duct run needs space above the hood and inside the cabinet. A recirculating hood needs space for a carbon filter instead. Neither shows up in the cutout dimension, and both can be the reason a hood that fits the hole still will not install. That is a bigger topic and we have covered it separately.
Common questions
Do all cooker hoods need a cabinet cutout?
No. Wall-mounted, chimney and island hoods mount to a wall or ceiling and have no aperture. Telescopic, canopy, built-in and downdraft hoods sit inside cabinetry and do need one. Check which type you are looking at before measuring.
How much wider than the hob should the hood be?
At minimum the same width, and ideally wider. A 90 cm hood at 898 mm over a 780 mm hob gives you about 60 mm of overhang on each side. Going narrower than the hob leaves the outer zones uncovered.
Why do two 60 cm telescopic hoods need different cutouts?
The product width is the visible fascia, which spans the full cabinet front. The cutout is the slot the mechanism drops into, and different motor and filter layouts need different slot sizes. In our Bosch range that slot varies from 460 mm to 598 mm on hoods that are all 598 mm wide.
What extraction rate do I need?
It depends on how you cook and how enclosed the kitchen is. Heavy wok cooking in a closed HDB kitchen is much more demanding than occasional pan frying in an open-plan layout. Our range runs from 260 m3/h to 1200 m3/h, and the figure is listed on each product page.
Can I reuse the cabinet from my old telescopic hood?
Only if the new hood needs the same aperture or a smaller one. Given the spread in our range, check the specific figure before assuming it is a straight swap. Enlarging a cabinet opening is easy, filling one in is not.