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What Size Vanity Light Do I Need?

Choose the right bathroom vanity light size from your mirror width, vanity layout, and fixture style with practical guidance for single and double vanities.

Direct answer

The right vanity light size is usually driven by mirror width first. A common starting point is a fixture around three-quarters of the mirror width, adjusted for single versus double vanity layouts.

target vanity light width = mirror width x about 0.75
Calculator

Vanity light size calculator

Light width
24-30" wide
Mirror width
in
Vanity width
in
Fixture count
ct
Ceiling height
in
Total light width
24-30" wide
Per fixture
25-29" each
Mounting cue
75-80" from floor

One bar light sized to the mirror. Keep vanity lighting sized to the mirror zone rather than the whole bathroom wall.

Vanity light sizing examples

24" mirror

18" to 22"

Small single vanity

36" mirror

24" to 30"

Common single vanity

48" mirror

34" to 40"

Wide single mirror

Two mirrors

Size each fixture separately

Often cleaner than one very long bar

Do not confuse fixture size with brightness

This page sizes the physical light, not the full lighting plan. Bulb output, diffuser style, side sconces, and ceiling lights still affect how useful the vanity lighting feels.

Plan the vanity light

  1. 1Measure the mirror width, not just the vanity width.
  2. 2Decide whether one bar light or separate fixtures fit the mirror layout.
  3. 3Keep the fixture visually tied to the mirror zone.
  4. 4Check mounting height, medicine cabinets, ceiling slope, and door swings before ordering.

FAQ

What size vanity light for a 36-inch vanity?

If one mirror fills most of a 36-inch vanity, a vanity light around 24" to 30" wide is a practical starting range. Adjust for mirror width and fixture style.

Should a vanity light be wider than the mirror?

Usually no. A vanity light often looks best when it is narrower than the mirror or sized to the mirror zone. Side sconces are a different layout and should be planned as a pair.

What size light works over a double vanity?

For two separate mirrors, size each light to its mirror. For one long mirror, compare one long bar with two fixtures over the sink zones so the light does not look undersized or awkwardly wide.

Sources & method

We reviewed these references while writing this answer. Figures are estimates — confirm safety-critical work with a professional. Last updated June 7, 2026.