Measure a round mirror straight across its centre, from one outside edge to the opposite edge. That measurement is the diameter: a 60 cm circular mirror is 60 cm wide and 60 cm high. For planning the wall space, measure the full outside size, including an attached frame.
The diameter tells you whether the circle fits. The position, frame and lighting then determine how it feels above the vanity. Once you have the measurements, compare round bathroom mirrors with lights to turn that outline into the style you want.
Measure the circle accurately
- Use a tape measure that can span the whole mirror without scratching the surface.
- Measure through the centre across the widest point, keeping the tape straight.
- Record the outside diameter in centimetres or millimetres.
- Check a second measurement at right angles; a true circle has the same width and height.
- Record the frame, depth and any separate hanging detail where they affect the installed space.
There is no need to remove an already mounted mirror simply to measure its visible diameter. For a loose mirror, support it securely and avoid resting the tape or tools on an exposed glass edge.
Glass diameter and frame diameter are not the same
If you measure the outside of the fitted frame, it is already included—do not add it again. If you only have the glass diameter and a frame extends evenly beyond it, add the outward frame width on both sides. For example, 60 cm of glass plus 2 cm beyond each edge gives a 64 cm outside diameter.
For a custom frame, the rebate, glass overlap and fitting clearance require separate measurements. Do not order a frame from the outside diameter alone. A bevelled glass edge is part of the glass rather than an added metal frame.
Mark the full outline above the vanity
Use a paper circle or removable marking method appropriate for the wall finish to compare diameters. Check the lowest point against the tap and splashback, the widest point against wall lights and the highest point against the ceiling or a shelf. Test the reflection at the standing heights of the people who use it.
A fixed percentage of the wall or one eye-level height will not suit every room. The basin position, vanity width and nearby fittings matter more than a universal two-thirds rule. If the wall is tall and narrow, oval LED mirrors may give you a better proportion.
Three in-stock circular designs to compare
60 cm frameless bevelled mirror — £69. A clean circular reflection with a decorative polished edge. It has no integrated lighting or demister, making it a simple choice where the room already has the illumination you want.
60 cm dual-light LED mirror — £128. The same diameter can create a different effect with front and rear lighting, dimming, three light colours and anti-fog. Include its depth and connection needs in your plan.
80 cm round Bluetooth mirror — £199. A larger circle gives the wall more presence, with speakers, a clock and anti-fog for everyday use. Mark the full 80 cm outline rather than judging size from the room photograph.
Prices and the linked in-stock options were checked on 27 October 2026. Any checkout promotion is applied separately.
Do not confuse delivery size with installed size
Packaging dimensions include protective materials and are larger than the mirror itself. Use the product’s mirror diameter and mounting information for your layout. A hanging strap can extend above the circle, while a backlit panel needs its intended rear spacing to create the glow.
Before fitting, use the supplied mounting system and fixings appropriate to the wall and mirror; a round shape does not automatically mean a picture hook is suitable. For an LED model, plan the electrical connection as well as the support.
Need a closer match to your furniture? Read our guides for cloakroom vanities, an 800 mm vanity and a 1000 mm vanity.
Enjoy free UK delivery, a 3-year warranty and free replacement if your mirror arrives damaged.