Bathroom Mirror Size Calculator
This bathroom mirror size calculator helps you choose a mirror that suits your vanity and sits at a comfortable height. Getting the size right matters: a mirror that is wider than the bench looks clumsy and can foul the walls or tapware, while one that is too small leaves the vanity looking bare. You enter the width of your vanity, how much bench you want to leave clear on each side, and the height of the countertop above the floor, and the calculator returns a recommended mirror width, the maximum width that would sit flush with the vanity, and sensible mounting heights. The common design rule is that a mirror should be a touch narrower than the vanity, with a small margin of bench showing on either side, and never wider than the vanity itself. For height, you leave a gap above the countertop so the mirror clears the tap and splashback, then centre it near eye level so it works for most people using the room. The defaults suit a typical single vanity, but you can dial in your own measurements. Treat the numbers as a starting guide and adjust for wall cabinets, sloped ceilings, feature lighting or a double vanity where two mirrors often look better than one.
Heights are above the floor. Leave 10 to 20 cm above the counter to clear the tap, and centre the mirror near eye level. Estimate only, adjust for cabinets and lighting.
How it works
The recommended width takes your vanity width and subtracts the clear bench you want on each side, twice, so a small margin of bench shows either side of the mirror. The maximum width is simply the vanity width, since a bathroom mirror should not overhang the bench. The bottom edge height adds a clearance of 15 cm to the countertop height so the mirror sits above the tap and splashback, and the centre line is set near average eye level at about 160 cm above the floor, which suits most households and keeps the mirror usable for both taller and shorter people.
Worked example
Your vanity is 90 cm wide, you want 5 cm of clear bench on each side, and the countertop sits 85 cm above the floor. The recommended mirror width is 90 minus 5 minus 5, which is 80 cm, with a maximum flush width of 90 cm. The bottom of the mirror goes 85 plus 15, which is 100 cm above the floor, clearing the tap, and the mirror is centred near eye level at about 160 cm. That leaves a comfortable, balanced look above a standard single vanity.
Related calculators
- Tile Calculator: tiles for a wall or floor.
- Tile Adhesive and Grout Calculator: adhesive and grout.
- Paint Calculator: litres of paint.
- Wallpaper Calculator: rolls needed.
- Square Meter Calculator: area in square metres.