Estimate joint compound, tape, and corner bead from the seams and corners a room actually contains, coat by coat, to the GA-214 finish level you are working to.
Change the inputs that matter to your decision. Optional assumptions stay collapsed until you need them.
Compound is consumed along the seams, so the sheet size matters as much as the area.
13 sheets make about 104 ft of flat seam and 84 ft of corner, finished to Level 4 with all-purpose compound.
Level 4 is the normal specification under flat paint: tape, fill, and a feathered finish coat on every seam.
| Sheets | 1312 × 4 ft board |
|---|---|
| Tapered seams | 78 ftFactory edges, which take the least compound |
| Butt seams | 26 ftCut ends, which have no taper to fill into |
| Inside corners | 84 ftDerived from the room dimensions |
| Coat 1 — bed the tape | 1.46 galCompound under the tape on every seam and corner |
| Coat 2 — fill | 1.15 galFills the taper and covers the tape edge |
| Coat 3 — finish | 0.94 galWide, thin coat feathered past the seam |
| Compound needed | 3.55 galWeighs about 43.3 lb mixed |
| Buy: 1 gallon box | 4 ×4 gal |
| Weight to carry | 48.8 lbThe containers above, not the compound the job consumes |
| Joint tape | 207 ftFlat seams and inside corners, with 10% for overlaps |
Per-coat rates are per linear foot of seam, which is what actually consumes compound; a room of the same area boarded with wider sheets has fewer seams and takes less mud. Setting-type compound is mixed from powder, so its bucket equivalent is the mixed volume.
Practical notes about the inputs, assumptions, and result.
Because compound is consumed along seams, not across the face. Two rooms of identical area, one boarded in 4 ft sheets and one in 8 ft sheets, have very different amounts of seam to tape and float. A rate expressed per square foot of wall cannot express that; a rate per linear foot of seam can.
Gypsum Association GA-214 finish levels. Level 3 is two coats, specified where texture or a heavy wall covering will hide the seam. Level 4 is the normal three-coat specification under flat paint. Level 5 adds a skim coat over the entire board face for gloss, dark colours, or critical raking light.
Roughly double a Level 4 job, because the skim covers the whole board rather than a band along each seam. It is the single largest lever in this calculator, so it is worth confirming the specification before ordering.
One is the compound the job consumes and the other is what you carry home. If a job needs 2.4 gallons you still carry a full 5-gallon bucket, and quoting only the bucket weight — as is easy to do — makes a small job look far heavier than it is.
No. Topping has too little adhesive to bed tape reliably; it is a finish-coat product. All-purpose does every coat, lightweight all-purpose sands more easily, and setting-type chemically hardens so several coats can go on in one day with less shrinkage.
Yes, by roughly 15% in this model. A taping tool or finishing box lays a more consistent bead than a knife and leaves less to scrape off and discard. The saving is real but it is not the reason to hire one — speed and consistency are.
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