What size shower enclosure do I need?

Measure the opening where the enclosure will sit. Standard UK shower enclosure sizes are 700, 760, 800, 900, 1000, 1100, 1200mm wide. The enclosure is typically 10-30mm smaller than the opening to allow for adjustment on the wall profiles. A minimum of 760mm × 760mm is recommended for comfort, with 900mm × 900mm being the most popular size.

Should I choose 6mm, 8mm or 10mm glass?

For a standard shower door or enclosure, 8mm toughened safety glass is the UK industry standard and offers a good balance of weight, rigidity and cost. 6mm is suitable for budget enclosures and bi-fold doors. 10mm glass is used for premium walk-in panels where the thicker glass provides better stability without a frame. All shower glass must be toughened safety glass to BS EN 12150.

What type of shower tray is best?

Stone resin trays are the most popular choice in the UK, offering a solid feel, good durability and reasonable cost (£80-200). Acrylic trays are lighter and cheaper (£40-100) but can flex. Slate-effect trays offer a premium look (£150-350). For a truly flush finish, a tiled wet room former with linear drain is the ultimate option but requires proper tanking.

Where should the shower waste be positioned?

Centre waste is the most common and works with most enclosure types. Offset waste positions the drain towards one end, which is useful when plumbing access is limited. End waste works well with walk-in showers where you want the drain away from the entry point. Always check that the waste position aligns with your floor joists and soil pipe route.

How many seal strips do I need for a shower enclosure?

A typical enclosed shower needs 4-6 seal strips: two vertical wall seals where the glass meets the wall profile, one or two bottom seals where glass meets the tray, and a door seal. Walk-in panels need fewer — typically 2 wall seals and a floor seal. Standard seal strips are 2m long and available in 4mm, 6mm and 8mm widths to match the glass thickness.

Shower Enclosure Calculator — Glass, Tray & Seal Sizing

Calculate shower enclosure panel sizes, tray dimensions, glass area, seal lengths and waste position based on your opening dimensions.

Opening Width

Width of the shower recess/opening

Opening Depth

Depth from wall to front edge

Enclosure Type

Walk-in panels are simplest; quadrant saves space

Glass Thickness

8mm is standard; 10mm for frameless walk-in

Tray Type

Stone resin is the most popular UK choice

Waste Position

Check alignment with floor joists

Enclosure Price (optional)

Total enclosure kit price

Tray Price (optional)

Shower tray price

Seal Strip Price (optional)

Per 2m seal strip

How We Calculate This

This calculator determines the correct shower enclosure panel sizes, tray dimensions and accessory quantities based on your opening measurements and chosen configuration.

The formula

Panel size = Opening width − Adjustment (15mm typical)

Glass area = Panel width × Panel height (per panel)

For a 900mm × 900mm rectangular enclosure at 1850mm height: front panel = 0.885 × 1.85 = 1.64 m², side panel = 0.885 × 1.85 = 1.64 m², total glass = 3.28 m².

Standard tray sizes (UK)

Quadrant: 800×800, 900×900, 1000×1000mm
Square: 700×700 to 1000×1000mm
Rectangular: 900×760 to 1700×800mm
Walk-in: 1200×800 to 1800×900mm

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Verify with your supplier.