Hi, I had an excellent cabinet maker make this for me. Measurements were intuitive for him. The drawers are not the full depth of the cabinet which is about 31". I wanted the pullouts for tidy storage. This setup holds the plumbing too. The drawers are set away from the side with the plumbing; the needed distance to allow for the plumbing. This setup is similar to what was put in decades ago but without the pullouts. The old setup had the plumbing came up from the basement into the old cupboard. Things got lost in that setup because it was like a deep cave. When I remodeled, I like the setup to house the plumbing, but wanted pullouts.

25.5" centerline toilet to face frame
Door is 16.5" inset
pullout is 20-7/8" long. The top shelf does hit the toilet tank so I put a bumper on it. The bottom drawer opens without the obstruction of the tank, about an inch more.