Glass shelves and table tops: thickness and measuring

Glass shelf thicknesses and spans, what the shelf load tool can and cannot tell you, and how to order and measure a toughened glass table top.

Written by the SW Glass team · Last updated

We cut glass shelves in 6, 8 or 10 mm, toughened unless you ask otherwise, with polished edges all round. Glass table tops are toughened, 10 or 12 mm thick, with square or rounded corners. For a shelf, the span between the supports decides the thickness. For a table top, measure the base, not the old glass.

What thickness should my glass shelf be?

Our glass thickness tool suggests a thickness from the span between the supports:

Span between supportsTool suggestion
Up to 500 mm6 mm toughened
500 to 800 mm8 mm toughened
Over 800 mm10 mm toughened, and check the sag in the shelf load tool too

These are planning suggestions, not a structural calculation. The span is bracket centre to bracket centre, or the clear distance between two channels.

How much weight will a glass shelf hold?

Our shelf load tool takes the span, depth, thickness and how the shelf is held, and gives the load it carries when that load is spread evenly along the shelf. It covers a shelf resting on a bracket at each end and a shelf held in a channel at each end.

Know its limits before you rely on it:

  • It is a planning guide, not a structural certification and not a design to BS EN 16612.
  • It assumes the load is spread evenly, the edges are clean and polished, and the brackets themselves carry the load.
  • A heavy object in the middle, a chipped edge or a weak bracket all reduce what the shelf holds.
  • It does not cover a shelf held along its whole back edge in a wall channel. That works differently, and the tool deliberately leaves it out.

If the load matters, ask us for a specification, and have anything load-bearing checked by an engineer.

How do I measure for a glass shelf?

  1. Step 1: Measure the span between the supports

    Bracket centre to bracket centre, or the clear distance between the two channels. This sets the thickness.

  2. Step 2: Measure the alcove at three heights

    Measure across the alcove at the height of the shelf, then 100 mm above and below. Walls are rarely parallel, so use the smallest of the three.

  3. Step 3: Allow clearance to fit it

    Order 3 mm to 5 mm under the smallest opening measurement, or the shelf will not go in. Or give us the opening, say it is an opening, and we take the clearance off.

  4. Step 4: Say how it is held and what it will carry

    Tell us whether it sits on brackets, in channels or on pins, and roughly what will go on it.

Our glass shelf measuring guide has the full version.

What glass table tops do you make?

Our table tops are toughened glass, 10 or 12 mm thick, with square or rounded corners. You can choose a polished or bevelled edge. Table tops and mirrors are the only pieces we bevel; see our guide to edge finishes. A special shape option lets you upload a template or drawing for a top that is not a rectangle.

How do I measure for a glass table top?

Measure the base, not the old glass.

  1. Measure the frame or base at its widest and its longest.
  2. Decide the overhang. Most tops overhang the frame by 10 mm to 25 mm on each side. Add it to the base size to get the glass size.
  3. Measure both diagonals of the base. If they differ, the base is out of square, so send us both figures rather than an average.
  4. Tell us the corner radius and how the top is supported: pads, a recessed frame or brackets.

A table top is the one piece where it is safe to give us the exact finished size you want. Say whether you want a full glass top or a protector over an existing surface, because they are different jobs. Our table top measuring guide covers each step.

How heavy is a glass table top?

Every millimetre of thickness weighs 2.5 kg per square metre. A 1200 × 700 mm top is 0.84 square metres, so in 10 mm it weighs about 0.84 × 25 = 21 kg. Check your size in the glass weight calculator. A weight is not a safe lifting limit: whoever lifts it should assess the task, the load, the route and the person, as the HSE manual handling guidance explains.

This is general guidance. For your project, follow the regulations and manufacturer instructions that apply, and ask your building control body, engineer or Gas Safe engineer where needed.

Where to go next

Price your shelf in the configurator.

Questions we get asked

Are your glass shelves toughened?

Yes. Every glass shelf we cut is toughened unless you ask otherwise.

Can I use the shelf load tool for a shelf in a back channel?

No. A shelf held along its back edge in a wall channel is a different case, and the tool does not cover it. Ask us for a specification.

Should I copy the size of my broken table top?

No. Measure the base it sat on and add the overhang you want. The old top may never have been right.

Can I have a bevelled table top?

Yes. Table tops can have polished or bevelled edges.

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