Reference
Standard Sizes for Drywall Estimating
The stock sizes every drywall estimate is counted in, from wall heights and studs to door openings, pails, bags and rolls.
Walls and framing
| Item | Standard sizes | Notes |
|---|---|---|
| Ceiling height | 8 ft, 9 ft, 10 ft (2.4, 2.7, 3.0 m) | 8 ft has long been the standard; many new homes have 9 ft main floors |
| Precut studs | 92-5/8 in (8 ft wall), 104-5/8 in (9 ft), 116-5/8 in (10 ft) | With a single bottom plate and a double top plate |
| Stud and joist spacing | 16 in or 24 in on centre (400 or 600 mm) | Partitions often 24 in; ceilings under 1/2 in board need 16 in across the joists or 24 in with sheets across |
| Plates | 2 × 4 (3-1/2 in) and 2 × 6 (5-1/2 in) | 2 × 6 plates for staggered-stud and plumbing walls |
| Steel studs | 1-5/8, 2-1/2, 3-5/8 and 6 in, in 25 to 20 gauge | Sold in 8, 9, 10 and 12 ft lengths, with matching track |
| Finished wall thickness | 4-1/2 in (2 × 4 + two layers of 1/2 in) | 4-3/4 in with 5/8 in board |
Openings
| Opening | Rough opening | Area deducted by the calculators |
|---|---|---|
| Pre-hung interior door | Slab + 2 in wide, + 2-1/2 in high: 34 × 82-1/2 in for a 32 × 80 in door | 20 sq ft per door (editable) |
| Exterior pre-hung door | Unit frame size + 1/2 in each way, from the maker | 20 sq ft |
| Window | Unit size + 1/2 in each way, from the maker | 15 sq ft per window (editable) |
| Closet bifold | By the door maker’s chart | Measure it |
Small openings are often not deducted when ordering board, because the sheet that covers them is cut out and the offcut is rarely usable; the calculators deduct them and then add waste.
Sheets, pails, bags and rolls
| Item | Stock sizes |
|---|---|
| Drywall sheets | 4 × 8, 9, 10, 12, 14 ft; 1,200 × 2,400, 2,700, 3,000 mm; 900 × 1,800 mm |
| Thickness | 1/4, 3/8, 1/2, 5/8 in (6.4, 9.5, 12.7, 15.9 mm) |
| Ready-mixed compound | 4.5 gal pails; boxes of about 3.5 gal; quarts and gallons for patching |
| Setting compound | 18 lb (lightweight) and 25 lb (standard) bags |
| Paper tape | 250 and 500 ft rolls |
| Mesh tape | 300 ft rolls |
| Corner bead | 8, 9 and 10 ft pieces |
| Drywall screws | 1, 5 and 25 lb boxes |
| Construction adhesive | 10 oz and 28 oz tubes |
| Insulation batts | 15 or 23 in wide for 16 or 24 in framing, in packs |
| Spray texture | 40 to 50 lb bags; aerosol cans for patches |
Waste allowances
| Room | Waste on sheets |
|---|---|
| Simple rectangular room, few openings | 10% |
| Rooms with many openings, angles or short walls | 15% |
| Cut-up rooms, stairwells, vaulted ceilings | 20% |
Sources
Precut stud lengths and lumber sizes: lumber dealers’ standard stock. Spacing and board thickness by framing: International Residential Code Table R702.3.5 and Gypsum Association GA-216. Rough openings: door and window makers’ installation sheets, which always govern. Pails, bags and rolls: manufacturers’ product listings. Waste allowances: estimating practice, labelled as the site’s estimate on each calculator.
Calculators that use this table
- The wall area calculator, the ceiling area calculator and the waste factor calculator.
- The wall stud calculator, the plates and blocking calculator, the rough opening calculator and the soffit and bulkhead calculator.
- The partition wall materials calculator and the drywall sheet calculator.
The guides how many sheets of drywall and framing a partition wall show the sizes in use.