Tools / Calculator

Bathroom Vanity Size Calculator

Enter your wall space and room depth and get the widest and deepest bathroom vanity that fits, with code clearances for the toilet and the floor in front.

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Units
What is at the ends

Measure the wall space from the side wall to the center of the toilet.

Result

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24-inch vanities at Simple Project

30-inch vanities at Simple Project

Floating vanities at Simple Project

How to measure

  • Wall space. Measure along the wall where the vanity will stand, from one obstacle to the next: wall to wall, wall to tub, or wall to door trim. If a toilet stands next to the vanity, measure from the side wall to the center of the toilet instead.
  • Room depth. Measure from the vanity wall straight out to whatever is opposite: a wall, a tub or the shower door.
  • Measure at the height of the countertop as well as at the floor. Baseboards and tile edges can take half an inch.

The rules the calculator uses

  • 15 inches from the center of the toilet to the side of the vanity. This is the minimum in US building codes. 18 inches is more comfortable if you have it.
  • 21 inches of clear floor in front of the vanity. This is also a code minimum. 30 inches lets two people pass.
  • 1 inch of play between two walls, so the cabinet can slide in and the walls do not need to be perfectly square.
  • Standard widths: 18, 20, 24, 30, 36, 42, 48, 60 and 72 inches. The calculator picks the widest one that fits.
  • Standard depths: 21 inches is the usual cabinet depth. Narrow-depth vanities are about 18 inches, slim ones 16, and the slimmest about 13.

What the calculator does not see

  • The door. A door that swings into the room needs its whole arc clear. Open it fully and check.
  • The drain and supply lines. Moving the sink a few inches along the wall is easy. Moving it to another wall is a plumbing job.
  • The mirror and the light. A vanity wider than the mirror above it looks unfinished, so plan them together.

Eleven vanity and sink types for tight rooms, with what each one saves, are in small bathroom vanity ideas. If you are not replacing the vanity, start with small bathroom ideas on a budget.

Codes differ by state and city. Check the local rules before a remodel that needs a permit.

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