Ceiling Grid Calculator
Main and cross runner lengths, hangers and fittings from ceiling size.
Quick answer
With the default inputs: Ceiling length 6 · Ceiling width 4 · Main runner spacing 1.2 etc.Main runner 21.0 m
Edit the inputs below to recalculate.Inputs
Result
Main runner
21.0m
| Ceiling area | 24.00m² |
| Cross tees | 63.0m |
| Perimeter trim | 21.0m |
| Hanger rods | 24bars |
| Runner clips | 70pcs |
| Cross tee clips | 105pcs |
| Main runner per m² incl. waste | 0.88m/m² |
| Cross tee per m² incl. waste | 2.63m/m² |
Main runner length is area ÷ spacing with 5% waste, excluding changes of level and feature ceilings. Rod length depends on the void and is counted separately, one expansion anchor per rod.
Reverse: known result, work out one input
Enter a target result; the other inputs stay fixed and this one is worked out.
Formula
| Area | A = length × width |
| Main runner | L = A ÷ spacing × (1 + waste) |
| Cross tees | L = A ÷ spacing × (1 + waste) |
| Perimeter | L = 2 × (length + width) × (1 + waste) |
| Hangers | N = (floor(L÷s)+1) × (floor(W÷s)+1) |
A 6 × 4 m ceiling with 1.2 m main runners, 0.4 m cross tees and 1.2 m hangers at 5% waste: 24 m², 21.0 m of runner, 63.0 m of cross tee, 21.0 m of trim and 24 hangers.
How to work it out
- Fix the hierarchy first: main runners (load bearing) run along the long axis, furring channels run across them.
- Main runner rows = room width ÷ main spacing, rounded up then plus one — both edges need a runner. 1.2 m for walk-on ceilings, 1.2-1.5 m otherwise.
- Furring rows = room length ÷ furring spacing, rounded up plus one. Spacing must not exceed 400 mm, because a 1200 mm plasterboard needs three supports.
- Hangers = main rows × (length ÷ hanger spacing + 1). Hanger spacing matches the main runners at 1.2 m, but no hanger may be more than 300 mm from a runner end.
- Perimeter channel by room perimeter, plus 5% for corners and shaped edges.
Where it goes wrong
- Dropping the plus one — using ⌈L/s⌉ instead of ⌈L/s⌉+1 gives five rows on a 6 m run at 1.2 m when six are needed, leaving the board edge unsupported and sagging.
- Setting furring at 600 mm — 600 mm is the stud spacing for partitions; ceiling furring must be 400 mm or closer or the board dishes between supports and the joints crack.
- Deriving hangers from runner metres — one 6 m runner needs six hangers, so five rows need thirty; dividing length alone undercounts by more than half.
- Ignoring imposed loads — walk-on ceilings, heavy pendants and fan coil units each need their own hanger sizing and spacing.
Material and cost
Galvanised channel 6-12 CNY/m, hanger sets (with anchor and clip) 2-4 CNY each, labour 25-40 CNY/m². Complete ceiling with board and labour 80-140 CNY/m², shaped ceilings from 150.
On site
- Ceilings over 100 m² or 15 m in one direction need movement joints, or thermal movement tears the boards.
- Heavy luminaires, maintenance walkways and grilles must not hang from the grid — give them independent anchors into the structure.
- Use galvanised or stainless hangers in wet rooms; ordinary zinc-plated hangers corrode through in a couple of years.
Basis
- GB 50210-2018 Code for acceptance of building decoration, Chapter 7 (suspended ceilings)
- GB/T 11981-2008 Cold-formed steel ceiling profiles
- JGJ 345-2014 Technical specification for public building ceilings
FAQ
Main runner versus cross tee?
Main runners carry the load directly from the hangers, have the larger section and run parallel to the short side; cross tees clip underneath and support the boards, their spacing setting the board span. Main spacing follows the hanger layout (within 1.2 m), cross spacing follows board strength (400 mm for plasterboard). Swap them and the ceiling sags.
Why cap hanger spacing at 1.2 m?
Main runners deflect under their own weight and the boards; wider spacing turns them into long simply-supported spans that sag in the middle and crack at the joints. The code caps spacing at 1.2 m and requires support within 300 mm of runner ends, since an overhanging end sags first. Heavy items like luminaires need their own hangers.
What is typical grid content per m²?
For a normal plasterboard ceiling: about 0.9-1.1 m/m² of main runner, 2.5-2.8 m/m² of cross tee and roughly 0.8 m/m² of perimeter trim, less in larger rooms. Calculating is more reliable than rules of thumb because small rooms carry proportionally more trim.
Cite this page
Use this format in reports, method statements or coursework. The link is permanent.
Building Calculator. Ceiling Grid Calculator. 2026-10-25. https://jianzhujisuan.com/en/ceiling-grid
Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.