What this calculator does
Bathroom mirror size works out recommended mirror width and height from your vanity and ceiling. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaMirror width = vanity width − 4 to 6 in (− 8 in for a double vanity); mirror height = ceiling height − (vanity height + 12 in)
The inputs explained
| Field | What to enter |
|---|---|
| Vanity width (in) | A number, measured in in. Starts at 36. |
| Vanity height (floor to top) (in) | A number, measured in in. Starts at 32. |
| Ceiling height (in) | A number, measured in in. Starts at 96. |
| Vanity type | Choose from Single, Double. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with vanity width
Every other input is held at the calculator’s starting values while vanity width varies. Select any row to load that scenario into the calculator.