Yes, measure.

I found that 16" of usable height (which is taller than the drawer sides, but shorter than the drawer front) was perfect for my appliances and for really large things stored on their sides (pizza pan, cutting boards, cookie sheets) and 10" was great for most pots and also for things like baking bans and casseroles turned on their sides. The front to depth back is also extremely important, my drawers on one wall are just under 23 inches instead of a standard 19 3/4 - those extra 3 inches give me room for a whole second row of pots which are 10-11" wide.

Ok my friend is ready to start the project - he came by to check out my lumber. He came up with a plan of three drawers - 5" and two 9". That is the inside height. I was thinking of doing only two drawers - maybe a 16" and a 8". Looking at everything I think maybe smaller drawers absorbing more smaller items might be more helpful. Confused.

I have a bottom drawer that is 9.5 inches deep (interior), thinking that would be enough. But then I thought that I would like to store some of the pans on their sides and found that it was not deep enough for my wok or paella pans, which would need 11"

The top drawer of this 3 drawer stack is deep enough that I am going to add a sliding drawer from Ikea on the inside to make it dual level for storing utensils.

Instead of two 9's for the lower drawers, you might consider an 8" and a 10", which would allow you a bit more flexibility for some taller items. I have a similar set up, with inside clearances of 3.5", 8.5", and 10.5" My deepest stock pot would not have fit in a 9"

Thank you! Photos are so helpful. Someone in the Cooking forum suggested I draw it out. I will attempt that later. For now here is a photo. A small project compared to most on here but a big step forward for me.

Is this for kitchen storage? It sounds like it but couldn't be sure.
Boy, if not, I could see an awesome big blanket/quilt drawer on the bottom and a smaller one for whatever on top.

I guess you do have to figure out what you want to keep there to tell you the height.

Here are a couple of my favorite understair set-ups and a link to some under-stair eye candy for you:
{{!gwi}}
{{!gwi}}

Here is a link that might be useful: stair storage ideas

Thank you for the photos and the link. Here is my attempt at a scale sketch of the area.