Bathtub & Shower Zone Clearance Calculator

The zone, at a glance

Both 406.9(C) and 410.10(D) draw the same box around a tub or shower: 3 ft out in every horizontal direction and 8 ft up from the top of the rim or threshold, including the space directly overhead. What the code does inside that box depends on the element.

The receptacle and suspended-fixture rules are flat prohibitions: the fixture cannot sit in the zone at all. The surface and recessed luminaire rule is not a prohibition but a listing requirement, and it applies only to fixtures over the tub or shower footprint.

Why suspended and surface fixtures differ

410.10(D) treats the two kinds of fixture differently because of reach. Cord-connected fixtures, chain-, cable-, or cord-suspended luminaires, lighting track, pendants, and ceiling paddle fans can be grabbed by a wet person standing on the tub rim, so they are barred from the whole 3 ft by 8 ft zone. A surface-mounted or recessed luminaire is fixed against the ceiling or wall and out of reach, so it is not on the prohibited list. Its only requirement is a location listing: over the tub or shower up to 8 ft it must be marked for damp locations, and for wet locations where it is subject to shower spray, which a fixture directly over a shower head normally is.

The two receptacle exceptions

406.9(C) is a flat prohibition inside the zone, but it carries two narrow permissions this tool surfaces rather than applies automatically. Exception No. 1 covers a bathroom smaller than the zone: the required receptacle may be installed opposite the tub rim or shower threshold on the farthest wall in the room. Exception No. 2, added by a 2020 Tentative Interim Amendment, permits a single receptacle in a dwelling unit for an electronic toilet or personal hygiene device such as a bidet seat, readily accessible, on the wall behind the toilet but not behind the tank, or on the opposite side of the toilet from the tub or shower. Because both are conditional, the tool reports a general receptacle in the zone as not permitted and leaves the exceptions for you to confirm.

Worked example: a tub alcove

A receptacle set 2 ft from the tub rim at 4 ft above the floor sits inside the zone, 2 ft is within 3 ft horizontally and 4 ft is within 8 ft vertically, so 406.9(C) does not permit it. Move that receptacle to the vanity wall 4 ft away and it clears the 3 ft band, though 210.8(A) still requires GFCI protection. A recessed can centered over the tub at 7 ft must be listed for damp locations under 410.10(D); if it is in the shower and catches spray, it must be listed for wet locations. A pendant light or a paddle fan anywhere in the 3 ft by 8 ft zone is simply not allowed.

Common mistakes

• Forgetting the zone goes straight up. The zone includes the space directly over the tub or shower, so a light or fan centered over the tub is in the zone even though it is 8 ft up.
• Treating a recessed can like a pendant. A recessed or surface luminaire is not barred from the zone; it only needs a damp or wet location listing when it is over the tub or shower.
• Using a damp-rated fixture in the spray. Over a shower head, subject to spray, the fixture must be listed for wet locations, not damp.
• Confusing the zone with the GFCI rule. 210.8(A) requires GFCI for every dwelling bathroom receptacle; the 406.9(C) zone is about placement, not GFCI.
• Relying on the exceptions by default. The small-bathroom and bidet-seat receptacle exceptions are conditional; confirm the room size or device before using them.

Frequently asked questions

How close can a receptacle be to a bathtub or shower?

No receptacle within 3 ft horizontally and 8 ft vertically of the top of the tub rim or shower threshold, per 406.9(C). A small bathroom may place the required receptacle on the farthest wall opposite the tub or shower, and a dwelling unit may have a single bidet-seat receptacle behind or beside the toilet.

Can you put a ceiling fan over a bathtub?

Not a ceiling-suspended paddle fan. 410.10(D) bars paddle fans, pendants, lighting track, and cord- or chain-suspended luminaires from the 3 ft by 8 ft zone, which includes the space directly over the tub.

Does a recessed light over a shower need a wet rating?

A luminaire over the tub or shower up to 8 ft must be listed for damp locations, and for wet locations where subject to shower spray. A recessed can directly over a shower head is normally treated as subject to spray, so it needs a wet-location listing.

Is the zone measured from the floor or the tub rim?

From the top of the bathtub rim or the shower stall threshold, not the floor. The 8 ft height and the 3 ft horizontal distance both start at that rim or threshold.

Does this cover the GFCI requirement?

No. GFCI protection for bathroom receptacles is 210.8(A), a separate rule that applies regardless of distance from the tub or shower. Use the GFCI Breaker Sizing calculator for that.

Related calculators

• GFCI Breaker Sizing Calculator: where GFCI protection is required in dwellings and how to size the breaker.
• Dwelling Receptacle Spacing Calculator: the 210.52 wall and countertop receptacle spacing rules.
• Swimming Pool & Spa Equipment Clearance Calculator: receptacle, luminaire, and switch clearances around pools and spas per NEC 680.22.
• Working Space Clearance Calculator: the working space in front of electrical equipment per NEC 110.26(A).