Vanity Mirror Size Calculator

The short answer

A bathroom mirror should be about 70% to 100% as wide as the vanity under it, and never wider. Over a 36 in vanity that’s 26 to 36 in, and 30 in is the standard width closest to 80% of it. Hang it with the bottom edge 5 to 10 in above the counter and the top about 72 to 77 in from the floor, a foot above standing eye level. On a double vanity, hang one mirror centered over each sink.

Lights go with the mirror: a bar about 3 in above it, or sconces at eye level on each side.

How to measure

1. Vanity width: measure across the top, side to side, including any overhang of the countertop. Still choosing the vanity? The bathroom vanity size calculator finds the widest one that fits your wall and brings its width here.
2. Vanity height: measure from the floor to the top of the counter.
3. The wall above it: check for outlets, a window or a recessed cabinet that the mirror has to clear, and where the light’s electrical box sits.

How to use the calculator

1. Enter the vanity’s width and height.
2. Choose one mirror or one per sink, and where the lights go: a bar above the mirror or sconces at its sides.
3. Read the result: the mirror width to look for, how high its bottom and top edges go, its height and where the lights go. Every standard width is listed as Fits, Tight or Doesn’t fit, with its share of the vanity.
4. Save or share it. Copy link keeps your numbers in the address.

How we calculate

The mirror’s width follows the vanity under it, and its height follows the counter and your eye level. If the wall has a window, an outlet or a cabinet in the way, that comes first.

• Width: 70% to 100% of the vanity: anywhere from 70% to 80%, or the vanity’s full width, but never wider. A width from 60% to 70% is Tight, a narrower size that suits a mirror with sconces beside it.
• Which width we pick: the standard width closest to 80% of the vanity. Standard widths run 20 to 66 in.
• Double vanity: one mirror per sink, each sized to half the vanity and centered over its sink. Double-sink vanities usually start at 48 in wide.
• Bottom edge: 5 to 10 in above the counter, room for the faucet and the splashes.
• Top edge: about 12 in above a standing eye level of 60 to 65 in, so 72 to 77 in from the floor.
• Lights: a light bar about 3 in above the mirror, which lands it 75 to 80 in from the floor. Sconces with their centers 60 to 66 in from the floor and 2 to 6 in from the mirror’s sides.

Worked examples

Worked example

A 36 in vanity, 32 in high

What we know

• Vanity: 36 in wide, 32 in high
• Mirrors: one; lights above the mirror

How it works out

1. Width: 70% to 100% of 36 in = 26 to 36 in; the standard width closest to 80% is 30 in.
2. Bottom edge: 32 in + 5 to 10 in = 37 to 42 in.
3. Top edge: eye level 60 to 65 in + 12 in = 72 to 77 in, so the mirror is 30 to 40 in tall.

For a 36 in vanity, look for a mirror 26 to 36 in wide, never wider than the vanity. 30 in is the standard width closest to 80% of it. Hang it with the bottom edge 37 to 42 in from the floor, 5 to 10 in above the counter, and the top about 72 to 77 in, a foot above standing eye level, which makes the mirror 30 to 40 in tall. Mount the light bar about 3 in above the mirror.

Worked example

A 60 in double vanity with a mirror over each sink

What we know

• Vanity: 60 in wide, 32 in high
• Mirrors: one per sink; lights at the sides

How it works out

1. Width: 70% to 100% of half of 60 in (30 in) = 21 to 30 in; the standard width closest to 80% is 24 in.
2. Bottom edge: 32 in + 5 to 10 in = 37 to 42 in.
3. Top edge: eye level 60 to 65 in + 12 in = 72 to 77 in, so the mirror is 30 to 40 in tall.

For a 60 in double vanity, hang a mirror centered over each sink, each 21 to 30 in wide so the pair stays inside the vanity. 24 in is the standard width closest to 80% of half the vanity. Hang them with the bottom edge 37 to 42 in from the floor, 5 to 10 in above the counter, and the top about 72 to 77 in, a foot above standing eye level, which makes each mirror 30 to 40 in tall. Mount sconces with their centers 60 to 66 in from the floor, 2 to 6 in from each side of each mirror.

Worked example

A 48 in vanity at comfort height, 36 in

What we know

• Vanity: 48 in wide, 36 in high
• Mirrors: one; lights above the mirror

How it works out

1. Width: 70% to 100% of 48 in = 34 to 48 in; the standard width closest to 80% is 36 in.
2. Bottom edge: 36 in + 5 to 10 in = 41 to 46 in.
3. Top edge: eye level 60 to 65 in + 12 in = 72 to 77 in, so the mirror is 26 to 36 in tall.

For a 48 in vanity, look for a mirror 34 to 48 in wide, never wider than the vanity. 36 in is the standard width closest to 80% of it. Hang it with the bottom edge 41 to 46 in from the floor, 5 to 10 in above the counter, and the top about 72 to 77 in, a foot above standing eye level, which makes the mirror 26 to 36 in tall. Mount the light bar about 3 in above the mirror.

Mirror size by vanity width

The mirror width for each standard vanity width, the standard mirror closest to 80% of it, and the pair of mirrors for a double vanity.

Mirror height by vanity height

Where the bottom and top edges go for common vanity heights, and the mirror height that fills the space between.

A taller vanity raises the bottom edge but not the top, so the mirror gets shorter: 30 to 40 in tall over a 32 in vanity, 26 to 36 in over a 36 in one.

Round mirrors and medicine cabinets

For a round mirror, use the width range for its diameter, and lean toward the lower end of it. Hang it with the same space above the counter as a rectangle.

A recessed medicine cabinet needs a wall cavity without pipes or wiring behind it, so check the wall before you buy.

Before you buy

Check the mirror’s outer size on the product page, frame included, and how it hangs: some mount portrait or landscape, which swaps the width and height. For a light bar, check its width against the mirror and leave the space above for its electrical box.

For the floor in front of the vanity, the bath mat size calculator gives the mat or runner that fits its width.