Most appliances I see will fit within the 16.5" undercab space I have with 28-30+" countertops. The 4.5qt Kitchenaid stand mixer doesn't stay out but is 14" high. The Dualit toaster does stay out currently and is 8.23" high. Toaster oven is 10" and micros I see about 12", coffeemaker 14.2" but check yours. Because of the steam when brewing we don't have one under a cab. A Vitamix assembled is too high but doesn't stay out anyway. I have enough space to store it unassembled when out for awhile. The extra depth of deep counters does lend itself to leaving more on the counters. Anyway, take out some of your stuff and measure it for yourself. But just don't think of 18" as some 'standard' meant for appliances, because it isn't.