If you want to measure for a custom mirror, the wall matters more than the mirror. A made-to-measure mirror is cut to a fixed size, so a small mistake at the start cannot be trimmed on site. This guide explains what to measure, what to photograph and what to leave for the site visit.
Quick answer: measure the finished wall, not an early construction opening. Note the width and height, the position of sockets and switches, skirting, door frames and the furniture below. Photograph the wall straight on. Then send the photo and approximate sizes to the mirror maker, who confirms the final size at a site measurement before fabrication.
Why measuring a custom mirror is different from buying a standard one
A standard retail mirror comes in a fixed size, so you choose the closest option and live with the gaps. A custom mirror reverses that. The mirror is planned around the wall, the vanity, the furniture and the finishes.
That is the advantage, and it is also the risk. Once the glass is cut, there is no adjusting it. Good measuring is mostly about finding out what the wall will really look like when the project is finished.
Start with the finished wall, not the rough wall
Tiles, stone cladding, paint build-up, skirting and wall panels all change the usable space. If the wall is still being finished, a measurement taken today can be wrong by the time the work is complete.
If the room is still under construction
Fix the final finishes first, or ask the mirror maker to measure once the surfaces are done. Measuring a bare block wall and then adding tiles is a common reason a mirror ends up too wide for its space.
If the room is already finished
You can measure straight away, but check what limits the space. A door frame, a light fitting, a corner or an air-conditioning grille can all shape where the mirror may go.
What to measure and write down
Use a rigid tape and write each figure on a simple sketch. Walls and floors are not always perfectly square, so one reading is not enough.
- Width: measure at more than one height, for example near the top, the middle and the bottom of the planned mirror area.
- Height: measure at more than one position along the wall, and note the starting point, such as the top of a vanity, a basin splashback or the floor.
- Edges: note what sits on each side, such as a corner, a door frame, a shelf or another wall.
- Distance from fixed points: record the gap from the floor, the ceiling and any furniture the mirror will sit above.
- Anything on the wall: sockets, switches, light fittings, vents and pipework.
Do not round every figure to a neat number. Write what you actually measured and let the site measurement confirm the final size.
Plan around sockets, switches and cut-outs
Sockets and switches near a mirror are a design decision, not an afterthought. Blue Lake can cut openings in a mirror for sockets, switches and fixtures, and the positions are checked at the site measurement before fabrication.
Decide early whether the mirror should cover a socket, leave it clear or use a cut-out. A cut-out needs to line up exactly, so it is best made once the position is final. If the mirror will include lighting, the power feed and driver position also need to be agreed first. Our LED mirror guide covers how lighting and the electrical point are planned together.
Think about the shape, not only the width and height
A rectangle needs two numbers. A rounded, arched or custom shape needs more: where the curve starts, how large the radius feels against the wall, and how the shape sits against ceiling lines and furniture. The mirror in the photo above has a rounded top corner that follows the wall rather than a plain rectangle.
For shape and edge ideas, the custom mirror buying guide compares rectangle, round, oval, arched and custom options. A simple paper or card template taped to the wall is a cheap way to see whether a shape suits the space before you commit.
Check how the mirror will physically reach the wall
This is the step many people skip. A large mirror still has to be carried through the building, so access matters as much as wall size.
- Check the width and height of the entrance, corridors and doors.
- Check whether a lift, stairs or a tight turn is on the route.
- Note the floor finish and any protection needed on the way in.
- Ask about parking or unloading access in your building.
For very large walls, one huge panel is not always the best answer. A planned layout of several aligned panels can be easier to move and install. Blue Lake plans multi-panel layouts around the wall and access, so mention a difficult route when you send your details.
Fixing method and wall type
The way the mirror is fixed depends on its size, the wall and the layout. The fixing method is selected around the wall, the mirror size and the project, so avoid choosing it from a photo alone.
Useful details to note are the wall material, whether it is tiled or painted, and whether the surface is flat. Heavy mirrors need a wall that can carry them, which is one reason a site check matters. Never rely on a rough guess for a large or heavy installation.
Photos that help the quote
Good photos save time and make the first discussion more accurate. Take them before you contact the supplier.
- One straight-on photo of the whole wall, taken from a few steps back.
- One close photo of any sockets, switches or fittings on the wall.
- One photo of the floor-to-wall junction or the vanity top below the mirror.
- A short note of your approximate width and height.
- A picture of the mirror style you like, if you have one.
Common measuring mistakes to avoid
- Measuring before the finishes are done. Tiles and skirting change the space.
- Taking one reading only. Walls and vanity tops are rarely perfectly square.
- Forgetting sockets and fittings. Late changes mean a new cut-out or a new mirror.
- Ignoring access. The mirror must reach the room in one piece.
- Treating your own figures as final. Use them for a first quote and let the site measurement confirm the size.
What affects the cost of a custom mirror
There is no single flat price, because every mirror is made to measure. The main factors are size, shape, mirror finish, edge treatment, frame, cut-outs, access and installation conditions. Accurate measurements help the first estimate, but the final written quote follows the site measurement. Send your wall photo and approximate dimensions through the Blue Lake contact page to start.
Frequently asked questions
Your measurements are useful for a first discussion and a rough direction. Blue Lake confirms the final size at a site measurement before fabrication, so a small error in your own figures does not become a cut mirror.
Measure width and height at several points and write down the smallest and largest readings. The mirror is then planned around the real wall rather than an assumed rectangle.
It helps. Decide whether the mirror should cover a socket, leave it clear or include a cut-out. The final cut-out positions are checked at the site measurement.
Yes. Large wall mirrors can be planned as aligned panels, which can also make carrying and installing easier. The layout depends on the wall and the access route.
You can try shapes and approximate sizes in the 3D glass configurator. The preview is illustrative, and the final size is confirmed after measurement.
