I believe standard is 18" above the counters.

If you're vertically challenged you certainly can lower them but realize appliances may not fit under the cabinets then.

I wouldn't go to 42 in..with 8 ft ceiling. The max height wall cabinet I would think of is 33 in high....then when you get to your molding decisions you have a bit more wiggle room and you can maintain a decent backsplash height. typical backsplash height is 18 inches..between 15 to 18 in backsplash is fine. Above sinks people place a shorter cabinet for more clearance while working. Backsplashes can be as short as 14 inches. If you have various runs in the kitchen and you want a much taller cabinet-39 or 42 inches for extra storage I would pick a spot to the side or end or different run rather than main work triangle zones. The top shelves on extra tall cabinets are too high to be handy in day to day use. Pick a special spot for this extra high cabinet....stick to 30-33 in high cabinet for the most part, with 8 foot ceilings. In your project, storage as a whole would be addressed with your configuration/entire plan....it should be a goal from the start to improve storage with efficient types of cabinets/inserts, etc. A concern is that you feel a need to raise the height so much because storage may be lacking...in final stages of your plan. Has your plan been reviewed here or anywhere multiple times/revisions??

I used to live in a place with ridiculously tiny kitchens--6 x 10, and everyone went with 42" cabs when they redid the kitchens. It's fine, except that you only have room for a very small soffit molding at the top and needed to tilt tall things to get them past the light rail.

Here's a pic of one, stolen from the listing:

Is it ideal? No, but if you have limited wall space it's worth it. I prefer a 39" or 40" over 42", but not all lines have those sizes, and in the pic above I would have used a simple quarter round instead of the wide molding on top and raised the OTR a bit, but that gives you an idea.

If you have a large kitchen with lots of cabinet space, I would go shorter.

I have 8' ceilings and used 39" upper cabinets. One thing you should check is the flatness of your ceiling. My ceilings varied by up to 3/4" at various points. With 39" uppers I was able to use a flat vertical crown averaging about 2 1/2" tall, scribed to the ceiling variation. This hides the ceiling variation well. With 42" cabinets, your ceiling would have to be very flat and level.

We're doing the same as DIY2Much2Do. I'd be hesitant to go more than 39".

In our last kitchen we used 42" uppers, and in our current kitchen 39" uppers. The old kitchen had a backsplash around 16" and the new one a space of 17.5". Notice I don't have a coffee maker or keep a mixer out, so that makes a difference for needed height. Both had/have 8' ceilings and both sets of cabinets are frameless. This means the doors open all the way to the top of the cabinet, no face frame there to attach a molding to. The biggest difference was how we finished at the ceiling. With 42" we didn't have room for a molding. There was a gap of 1" or so that is probably full of dusty gunk.

This is the kind of thing that can make you crazy. I had thought about it. Reasoned through it. Decided on 36". Then I read something that says to me, in a friendly little voice, "Hey, you could probably make those cabinets even taller if you wanted to!" Then I second guess myself. I want a bit of molding and I want more space under the cabinets for appliances. Like being able to push my KA all the way back when I'm using it. So no 42" for me.

Thank you all for being my sounding board! So many questions my husband is tired of me constantly changing my mind! I'm not sure I blame him :)

suzanne, love your new kitchen! Thanks for the visual.

You made the right decision! We have 40" uppers and 8' ceilings and the trim options were not very good. We came up with a less than ideal solution and we are still implementing it. Unfortunately the ceiling differences are more obvious when you have a small trim. If you can use a taller trim I think you can hide it better.

Also, I have put nothing in to my top shelves because they are too much of a pain to reach. Unless you have a tiny kitchen and need every inch, I don't think it is worth it.

Make sure that the upper cabinets on either side of your stove (if there are cabinets on either side of your stove) are the minimum height required by the stove manufacturer to be safe and check your local codes otherwise you won't pass inspection. For gas appliances 16 inches between the top of the stove and the bottom of the cabinet is too small. The norm is 18 inches.

I didn't even consider the clearance for the range! Ours is indeed gas.

I have no shortage of things I could have put on upper shelves. And with my 5 year old sous chef, there's always a stool in the kitchen anyway. But that's ok. I'll find a place for everything in 36" cabinets. They'll still be taller than my current ones.