Inputs
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CSV/PDF export
Live math
Results
| Metric | Value |
|---|
Formula used
We model hangers at intersections of main runners and along-runner positions. Let
D⊥ be the dimension perpendicular to runner direction,
and D∥ the parallel dimension.
- Runner lines:
Nr = ⌊(D⊥ - Or)/Sr⌋ + 1ifOr ≤ D⊥, else 0. - Hangers per line:
n = ⌊(D∥ - Oh)/Sh⌋ + 1ifOh ≤ D∥, else 0. - Total raw intersections:
N = Nr × n. - Rounding modes:
- Ceil per-line:
n = ⌈(D∥ - Oh)/Sh⌉ + 1before multiplying. - Ceil after total: compute
Nraw, then apply ceil after factors.
- Ceil per-line:
- Safety & wastage:
N' = ⌈(N × safety) × (1 + waste%)⌉. - Fixtures:
Nfinal = N' + extras.
Notes: If “Centered grid” is enabled, offsets are set to half the spacing, simplifying balanced layouts near edges.
How to use this calculator
- Select units, orientation, and rounding preference.
- Enter room length and width in chosen units.
- Set runner spacing and hanger spacing; choose offsets or enable a centered grid.
- Optionally add a safety factor, waste percentage, wire gauge, and fixture extras.
- Press Calculate to see lines, spacing counts, and totals.
- Use Download CSV or Download PDF to export your results.
Typical guidance: runner spacing 1200 mm, hanger spacing 1200 mm; offsets 300 mm to clear edges and services. Always follow manufacturer guidance and local codes.
Example data
| # | Length | Width | Runner spacing | Hanger spacing | Offsets (runner/hanger) | Centered | Safety | Waste % | Extras | Estimated hangers |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 6 m | 4 m | 1200 mm | 1200 mm | 300 / 300 mm | No | 1.10 | 2 | 0 | — |
| 2 | 20 ft | 12 ft | 48 in | 48 in | 12 / 12 in | Yes | 1.15 | 5 | 4 | — |
FAQs
Common practice is 1200 mm between runners and 1200 mm along runners. Always verify manufacturer requirements and local codes for your specific system and loads.
Not directly. Hangers are primarily driven by the suspension grid. Board size influences furring channels and joint layout but not the basic hanger intersection density.
Offsets set the distance from edges to the first line or hanger. Larger offsets reduce interior intersections but may require perimeter support; centered grids balance margins at both edges.
“Ceil per-line” guarantees every runner line has enough hanger points individually. “Ceil after total” may yield fewer hangers but expects balanced distribution by the installer.
The calculator multiplies the raw total by your safety factor and increases it by the waste percentage, then rounds up to the nearest whole hanger.
Yes. Use the “Extra hangers for fixtures” input to manually add hangers for lights, diffusers, or other concentrated loads in your layout.
No. This tool sizes counts, not structural capacity. Confirm wire gauge, hanger type, and allowable loads with the manufacturer and your project specifications.
All calculations convert inputs to meters internally. Displayed unit hints update automatically based on your selection for a smooth workflow.