SettingsSettings for this calculationUS
The horizontal run length of the boxed-in soffit or bulkhead.
Measure the full length the soffit or bulkhead runs along the wall or ceiling.
How far the soffit drops down from the ceiling on each visible side face.
This sets the height of the two vertical side faces that need to be wrapped.
The width of the flat bottom face of the boxed-in soffit or bulkhead.
Measure across the underside of the soffit from one side face to the other.
Total wrap area
64.19 sq ft
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Soffit/Bulkhead Drywall Wrap Area Calculator: 64.19 sq ft — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Wrap area = 2 × (depth × length) for the two side faces + (bottom width × length) for the bottom face, assuming the top of the soffit is closed against the structure above
Inputs used
- Soffit/Bulkhead Length
- 19.5 ft
- Depth (Vertical Drop of Side Faces)
- 11.75 in
- Bottom Face Width
- 16 in
What this calculation does not cover
- Assumes the box dies into a wall at both ends. A soffit that stops in the open has a return face of depth x bottom width at that end — trivial as area, but it brings two more outside corners with it, and the corners are the part that costs time.
- Area is not the finishing. Every boxed soffit carries two outside corners for its whole length, so a 6 m (20 ft) run needs 12 m (39 ft) of corner bead before a single flat joint is taped, and that quantity tracks the run rather than the area. Boards ordered off this figure with the bead ordered off nothing is how the job stops on the second morning.
- Says nothing about board thickness or how the box is framed. The bottom is a ceiling, and 12.5 mm board on framing at 600 mm centers sags over a horizontal face — 15 mm board or framing at 400 mm is the fix, and either one changes the sheet order this area converts into.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- Wrap area = 2 × (depth × length) for the two side faces + (bottom width × length) for the bottom face, assuming the top of the soffit is closed against the structure above
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