Bathroom fixtures dimensions and basic layout:
You don't need exact dimensions for each of your bathroom fixtures when design your bathroom layout, instead, simply draw rectangular or square boxes to "reserve" the space for each of the bathroom fixtures. The most challenge part in planning a bathroom layout, is to make sure your planned spot for your bathroom fixtures are ok with the plumbing, especially drain pipes. In most renovation cases, bathroom drains are usually difficult to relocate, as they are often constrained by the existing floor joists, and other utility ducts and pipes. Try not to move the drains for your bathroom toilet, bathtub, bathroom sink, or shower stall unless it is absolutely necessary and your plumber gave you a green light.