Bosch 300 Series 18-inch dishwasher review: narrow, and how much you give up

This one is for a kitchen with an 18-inch hole and nothing wider to offer. I haven't run this machine. Nor could I find a published lab test of it, so everything below is Bosch's rating, a store's listing or my opinion of them. Treat the score that way.

The gap decides this

Bosch gives the appliance as 32 1/16 inches high and 22 9/16 deep, with a width of 17.63 in. Its required cutout is 32 1/8 by 17 3/4 by 21 2/3 inches. Abt's page gives a cutout width of 17.63 inches, a cutout depth of 24 inches and a height of 32.69 inches for the machine itself. Those don't agree. Go by the Bosch installation sheet, and measure the opening at the front and the back, because old cabinets drift.

If your gap is 24 inches, stop here and read how the 18-inch compares with a 24-inch Whirlpool. Buying narrow on purpose only makes sense if you need the extra 6 inches for a cabinet or a walkway.

Who it suits

Bosch rates it at 10 settings. That's the top of the 8 to 10 that Abt's buying guide gives for 18-inch models. IKEA Indonesia's size guide, a retailer's rule of thumb and not a standard, gives 1 to 2 people 6 to 8 settings and 3 to 4 people 10 to 12. It also says 8 to 10 is usually enough for smaller households. So I'd say one to three people. Four is possible if you run it every day and hand wash the big pots.

The word "compact" misleads here. The trade standard behind what a place setting means calls anything with 8 settings or more standard, and this is one. ENERGY STAR warns that compact models may use more energy over time, but that warning is about machines under 8 settings. Its ENERGY STAR status reads Certified. Bosch rates it at 240 kWh and 591 gal a year.

What you give up

Mostly plates. A 24-inch model starts at 12 settings in Abt's guide and runs to 16, so you'd be running this one more often for the same dishes.

You don't give up much in the way of hardware:

• A third rack, and a stainless tub.
• An upper rack that Abt says adjusts to 9 positions.
• 5 cycles: Heavy, Auto, Normal, Rinse and Favorite, per Bosch.
• Wi-Fi through Home Connect, and an AquaStop leak system.
• ADA compliance, per Abt.

Abt lists no interior light and no hard food disposer. I'd expect a filter to rinse by hand.

The noise rating is 46 dBA, Bosch's number, not a measurement. Bosch's page also calls Bosch "the quietest dishwasher brand in the U.S." with an asterisk. I'd ignore that line. The rating is what you can compare.

Where I'd worry

Width is the thing no spec sheet solves. Bosch's page gives no interior dimensions, and a narrow tub has to take the same dinner plate as a wide one. Tom's Guide warns that racks packed for high setting counts can have tines so close that thick plates touch. That's about dense racks in general, not this model. Still, I'd take your thickest plate and your favorite baking tray to a showroom before paying.

Owner ratings are thin comfort. Bosch's own page showed 4.6 from 93 reviews when I read it on November 2, 2026, and it's Bosch's page.

Price and stock

The price checked November 2, 2026 is $1,099. On that date Bosch's own page marked it out of stock, while Abt let you add it to a cart. So check stock before you plan the install around a date.

Narrow doesn't mean cheap. Set that $1,099 against the $949 list price of the 24-inch Whirlpool, or read the other small-kitchen picks first. A renter with no plumbed slot can't use this at all, and should look at the countertop Danby there.

What would make me skip it

• You have 24 inches free. Skip it.
• Four or more people eat at home most days.
• You rent and can't touch the plumbing.
• You want proof from a lab before spending this much. I couldn't find one I could open.

If you're unsure which size fits the household, the home sizer runs the same rules of thumb, and the product page has the full spec list.