The IRC minimums for a bathroom: 15 inches from the toilet centerline to a side wall, 21 inches in front of the toilet, 21 inches in front of a lavatory, and 24 inches in front of the shower opening. Code is the legal floor; comfort wants roughly a third more at every fixture. Local codes can differ.

Source: IRC Figure R307.1 and P2708.1, checked August 2026. Local codes amend these; always verify yours.
The free bathroom planner runs the code check and the comfort guidelines separately on every drag, and prices the plumbing consequences of each fix. Deep dives: toilet clearances and shower clearances.
Code minimums are what an inspector can enforce; comfort guidelines are what makes the room pleasant to use. A bathroom can be fully legal and still feel cramped, which is exactly why the planner shows the two layers separately instead of blending them.
Yes: a powder room follows the same fixture clearances, which is why the classic minimum half bath is about 30 by 60 inches. The small-bathroom guide walks through what fits at each room size.
Formally the plan reviewer and inspector, but by then changes are expensive. Checking clearances at the layout stage costs nothing: draw the room, drag the fixtures, and fix problems while they are still free to fix.