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Suspended Ceiling Calculator — Tiles, Grid & Hangers
Calculate ceiling tiles, main runners, cross tees, wall angle trim and suspension hangers for a suspended ceiling installation.
Internal room length in metres
Internal room width in metres
Drop from soffit to grid (min 100mm) — used to estimate hanger wire length
Extra tiles for edge cuts (10% recommended)
Ceiling area per suspension wire (trade rule: area ÷ 1.6 m²)
Spacing between perimeter fixing clips (default 0.6m)
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How We Calculate This
This calculator works out all the components needed for a suspended ceiling grid system. It calculates based on standard grid layouts with main runners at 1200mm centres and cross tees sized to match your chosen tile format.
How the grid works
- Main runners (main tees): Run parallel to the longest wall at 1200mm centres; the perimeter tile edges sit on the wall angle, not a main tee
- 1200mm cross tees: Clip between the main runners at 600mm centres to form 1200×600 modules
- 600mm short cross tees: For 600×600 tiles only — drop into the centre slot of each 1200mm cross tee to split the module into two 600×600 tiles
- Wall angle: L-shaped trim fixed around the full perimeter, sold in 3m lengths
- Suspension wires: One hanger per 1.6 m² of ceiling (max 1200mm centres along each runner), fixed to the structure above
Key calculations
- Tiles: Grid layout based on room dimensions, plus wastage for edge cuts
- Main runners: round(width ÷ 1.2) main-tee lines, each spanning the room length and cut from 3600/3000mm stock (≈ area × 0.232 lengths)
- Cross tees: ≈ area × 1.383 of 1200mm cross tees, plus the same again in 600mm short tees for 600×600 tiles
- Hangers: Ceiling area ÷ 1.6
- Wall angle: Perimeter ÷ 3m lengths, rounded up
Wastage of 10% is recommended for tiles as perimeter tiles require cutting. Complex room shapes or rooms with many columns may need higher wastage allowances.
Frequently Asked Questions
For 600x600mm tiles you need approximately 2.78 tiles per m² (before wastage). For 1200x600mm tiles you need approximately 1.39 tiles per m². Always add 10% extra for cuts at the edges of the room, as perimeter tiles are almost always cut to fit.
Main runners (also called main tees) are spaced at 1200mm centres. They run parallel to the longest wall to minimise the number of joins, and the perimeter tile edges are carried by the wall angle rather than a main tee. Standard main runners come in 3600mm or 3000mm lengths and are joined end-to-end with splice connectors. A common trade estimate is roughly 0.23 main-tee lengths (3600mm) per m² of ceiling.
Yes. A 600x600 exposed grid uses two cross-tee lengths. The 1200mm cross tees clip between the main runners at 600mm centres to form 1200x600 modules, then a 600mm short cross tee drops into the centre slot of each 1200mm cross tee to split that module into two 600x600 tiles. So you need roughly equal numbers of each (about 1.4 of each per m²). A 1200x600 tile layout only needs the 1200mm cross tees — no short tees.
The recognised trade estimating rule is one suspension wire (hanger) per 1.6 m² of ceiling area, i.e. ceiling area divided by 1.6. For a typical 4m x 5m room (20 m²) that is about 13 hangers. Geometrically, wires are fixed every 1200mm along each main runner with the first wire within roughly 600mm of each wall, and no more than 1200mm apart in any direction.
Wall angle (also called perimeter trim or wall channel) is an L-shaped metal strip fixed around the room perimeter to support the edges of the suspended ceiling grid. You need enough to cover the full perimeter of the room. It is sold in 3m lengths, so divide the perimeter by 3 and round up (allowing extra for corner cuts).
Run it once for each rectangular section and add the tile, main runner, cross tee and suspension hanger counts. Those quantities follow the ceiling area and grid layout, so entering the overall bounding dimensions instead would over-order them by the area of the missing notch. Keep the 10% tile wastage on each run: the real grid runs continuously through the join between sections, so its alignment in the second section can add a few extra cut tiles. The perimeter items (the wall angle trim and its perimeter fixing clips) are the figures you should not add up from the section runs, because the join line between sections is not a wall and summing section perimeters counts it twice. Use an exact shortcut instead: for a room shaped like a rectangle with a corner cut off, the true perimeter is exactly 2 x (overall length + overall width) of the bounding rectangle, because the notch walls line up with the wall sections they replace. Divide that by 3m and round up for the wall angle lengths, and space the perimeter clips along that same true perimeter.
Yes, but you must use moisture-resistant ceiling tiles rated for high-humidity environments. Standard mineral fibre tiles will sag and deteriorate in humid conditions. Look for tiles with a RH95 rating. The grid system itself is galvanised steel and is suitable for wet areas. Ensure adequate ventilation above the ceiling void.
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Last updated: July 2026
Verified against UK standards · estimates only, confirm with your supplier.