Drywall ceiling calculator
Drywall ceiling
calculator
Calculate drywall or plasterboard sheets for a suspended ceiling, including UD perimeter guides, CD profiles, hangers, anchors, screws, joint tape, compound and waste.
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Based on your result
What you'll need
Quantities update after every calculation. Brands and prices can be chosen at your preferred store.
- Drywall sheets
- Ceiling boards plus your waste allowance
- Calculate above
- Ceiling profiles
- UD perimeter tracks and CD main runners
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- Hangers
- Suspend the frame from the slab
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- Screws
- Fix sheets to the profiles
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- Joint compound
- Fills and smooths the joints
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The maths
How we work out your ceiling
The ceiling footprint is multiplied by the number of board layers, padded by the waste allowance you choose, and divided by the sheet size. The suspended metal frame — CD main runners with a UD perimeter — plus its hangers are sized from the room and the profile spacing.
sheets = ⌈ board area × (1 + waste) ÷ sheet size ⌉
CD runners = (⌈ width ÷ spacing ⌉ + 1) × length
hangers = CD length ÷ 4 ft
- 10–20%
- waste (you choose)
- 16 / 24 in
- profile spacing
- 1 / 4 ft
- hanger spacing
- 32–48 ft²
- per sheet
- 2 layers
- for acoustic / fire
- ft ↔ m
- converted automatically
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01
Measure the ceiling
Length multiplied by width gives the footprint the boards have to cover.
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02
Choose your layers
One layer suits most rooms; a second adds acoustic and fire performance overhead.
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03
Apply the waste allowance
Pick 10, 15 or 20% — offset and staggered layouts create more offcuts than a plain grid.
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04
Suspend the frame
CD runners sit at your spacing inside a UD perimeter, held up by hangers roughly every 4 ft.
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05
Finish overhead
Screws, tape and compound scale with the sheet count — ceilings use a few more screws than walls.
Good to know
Ceiling questions, answered
Ten percent is fine for a plain grid where boards run wall to wall. Bump it to 15 or 20% for smaller rooms, offset joints or lots of cuts around lights and vents — a ceiling is less forgiving than a wall because every offcut falls out.
One layer is standard. A second layer noticeably improves sound insulation between floors and raises the fire rating, which is why it is common in flats and under living spaces. It doubles the boards and fixings.
A suspended ceiling frame hangs below the structural slab or joists on adjustable hangers, roughly one every 4 ft along each runner. They set the drop height and let you level the frame perfectly.
CD main runners at 16 inches (400 mm) give a flatter, stiffer ceiling and are the safe default; 24 inches (600 mm) uses less metal on smaller single-layer ceilings. Closer spacing means more profile and more hangers.
You can where joists are level and correctly spaced, which skips the suspended frame. This calculator sizes a suspended CD/UD grid — the more common approach — so treat the frame figures as the upper bound.
Yes. Switch to metres and dimensions, sheet sizes and profile lengths convert automatically, with results shown in square and linear metres.
Boards are fixed overhead against gravity, so they are screwed at closer centres to hold flat and avoid sagging over time — the calculator already uses a higher screw rate for ceilings.