Before you start: tools & quick rules

• Measure to the millimetre. Round down, not up—glass can’t “compress.”
• Confirm the base is level. Wobble or twist will show once a perfectly flat glass sheet is on top. Use thin packers if needed.
• Decide the look: floating overhang vs flush, square vs rounded corners, transparent vs tinted/frosted.

Safety note: For table tops in busy homes, safety glass is recommended. Tempered glass is tested to BS EN 12150; impact performance is classified under BS EN 12600. See general homeowner guidance in Approved Document K.

Step-by-step measuring (by shape)

1) Rectangular tops (most common)

1. Measure base length and width in millimetres. If the top will sit inside a frame/lip, measure the clear opening at several points and use the smallest figures.
2. Choose your overhang if the glass sits on top of legs/standards. Typical overhang looks balanced at 20–40 mm per side for coffee/side tables and 25–50 mm for dining tables.
3. Calculate glass size: Glass length = base length + (2 × overhang); Glass width = base width + (2 × overhang).
4. Check between legs so knees don’t hit glass edges; you may reduce overhang on the long sides if seating is tight.

2) Round tops

1. Find maximum diameter you want, measured edge-to-edge through the centre.
2. If the base is smaller, decide your uniform overhang (e.g., 30 mm all around) and add twice that to the base diameter.
3. For frames with a circular lip, measure the clear internal diameter at several points and use the smallest figure.

3) Oval / racetrack

1. Measure overall length and overall width at the widest points.
2. Note if the ends are true semicircles or have custom radii. If unsure, trace a paper template.

4) Irregular or template-only shapes

For live-edge timber, antique furniture, or asymmetric frames, create a paper/card template:

1. Lay large paper on the base and tape it so it won’t move.
2. Trace the required perimeter (include the desired overhang). Mark the orientation and “TOP”.
3. Measure a couple of known distances on the template (for scale checking) and add these as written dimensions.
4. Roll and label the template; your fabricator can digitise it for cutting.

Choosing thickness, edges & corners

Thickness affects stiffness, weight and feel. For most domestic tops:

Edge finishes

• Flat-polished: crisp, modern; our most popular for table tops.
• Pencil-polished (slight round): soft to touch, family-friendly.
• Bevel: decorative chamfer; suits traditional furniture.

Corner radius (how to specify)

Rounded corners reduce snagging and feel safer. You can specify a radius in millimetres (e.g., R10, R20). A quick way to visualise is to hold a coin to the corner: a UK 10p is ~24 mm diameter, so a corner that “matches” half a 10p looks roughly R12. For perfect matches to a base, supply a template.

Overhang, supports & weight

As a rule of thumb, keep unsupported overhangs to ≤ 30–50 mm for everyday tables unless the glass is thick (10–12 mm) and the base is very stable. If your base has small contact points (e.g., four pegs), use clear silicone bumpers or neoprene pads at each point to spread load and prevent slip.

Approximate weight guide: standard glass is about 2.5 kg per m² per mm of thickness. A 1000 × 600 mm top in 10 mm weighs ~15 kg. Make sure the base and location can handle lifting, and avoid cantilevering heavy tops where children might pull on them.

Care, cleaning & safety notes

• Use non-abrasive cleaners and microfibre cloths; avoid harsh scouring pads.
• Place coasters/trivets under hot items; thermal shock can crack glass. (Tempered glass increases resistance but is not indestructible—see performance basics under BS EN 12150.)
• If the table is in a route where people might collide, consider tempered glass or even laminated options; general safety glazing guidance appears in Part K summaries.

Printable checklist (tick before ordering)

Tip: For unusual furniture or lips/rebates, a paper template is the most reliable method.

Ready to order?

Once you have sizes, thickness and finish locked in, you can choose shapes, edgework and extras on our glass table top page. If you’re unsure about thickness or overhang, share a quick photo of your base and measurements—our team will sanity-check your spec.

This article is a practical guide. For wider home safety rules around impact and collision, consult Approved Document K and the relevant British/European standards (e.g., BS EN 12150, BS EN 12600).