Drywall Mud Calculator

Multiply drywall area by the finish-level rate. Level 3 (texture-ready): 0.040 lb/sq ft (0.20 kg/m²). Level 4 (paint-ready, standard residential): 0.130 lb/sq ft (0.63 kg/m²). Level 5 (glossy/critical lighting): 0.180 lb/sq ft (0.88 kg/m²). For a 500 sq ft (46 m²) Level 4 job: 65 lb (29.5 kg) of mud, which is 5.4 gallons (20.4 L), about two 5-gallon (19 L) buckets. The calculator above accepts either a direct area or full room dimensions and handles the math.

At Level 4 (paint-ready, most residential): 100 sq ft (9.3 m²) needs 13 lb (5.9 kg) / ~1 gallon (3.8 L), one 1-gallon bucket. At Level 3 (texture): 4 lb (1.8 kg) / 0.33 gallon (1.2 L), half a 1-gallon bucket. At Level 5 (glossy): 18 lb (8.2 kg) / 1.5 gallons (5.7 L), one 1.5-2 gallon bucket or part of a 5-gallon (19 L). The reference table on this page gives the full grid. Multiply by your actual area.

All-purpose (the green-lid USG bucket): standard mud for tape, fill, and finish coats. Coverage 0.130 lb/sq ft (0.63 kg/m²) Level 4. Lightweight (blue lid): 30% lighter, easier to sand, but slightly weaker. Good for finish coats only, not first taping. Same coverage rate. Quick-set (powdered, mix on site): 20-90 minute working time, used for filling deep cracks and same-day repairs. Buy by the bag, not the bucket. The calculator's rate works for all-purpose and lightweight equally.

Finish level sets the coverage rate. Level 3 uses 0.040 lb/sq ft (0.20 kg/m²). Three coats over taped seams only, with the surface getting covered by texture or a thick paint. Level 4 uses 0.130 lb/sq ft (0.63 kg/m²). Three coats over seams plus a wider feather, ready for standard paint. Level 5 uses 0.180 lb/sq ft (0.88 kg/m²). Level 4 plus a full skim coat over the entire wall, required for glossy paint and critical lighting. Going from Level 4 to Level 5 nearly doubles your mud cost.

Roughly 0.043 lb/sq ft (0.21 kg/m²) per coat for Level 4 (three coats × 0.043 ≈ 0.130 lb/sq ft / 0.63 kg/m² total). The first coat (tape coat) is thicker and goes on the seams only, about 0.060 lb/sq ft (0.29 kg/m²) of seam length. Second coat (fill coat) widens the feather. Third coat (skim coat) is thin, just flattening the surface. For Level 5, add a fourth full-surface skim. That's where the extra 0.050 lb/sq ft (0.24 kg/m²) comes from. The calculator gives the total. Divide by 3 for a per-coat estimate.

Yes. Buy one extra bucket beyond the calculated number. Mud is cheap (~$15-20 per 5-gallon / 19 L bucket) and a partial bucket left over is more useful than running short mid-job. Mud also dries out and skins over once opened, so it's not worth saving partial buckets for projects months later. Add 10-15% to whatever the calculator says if you're a first-time DIYer. Second coats often go heavier than they should until you get the feel.

Pre-mixed (ready-mix) all-purpose: comes in 1-gallon (3.8 L), 3.5-gallon (13 L), 4.5-gallon (17 L), and 5-gallon (19 L) buckets, ready to use, slow-drying. The standard for residential. Powdered (setting-type, hot mud): comes in bags, mix with water on site, sets chemically in 20-90 minutes. Powdered is used for filling deep gaps, same-day repairs, and jobs where you can't wait 24 hours between coats. The calculator's gallon output applies to pre-mixed. For powdered, weight is what matters, and the same rate (0.130 lb/sq ft / 0.63 kg/m² Level 4) holds.

Imperial SKUs: 1 gal (3.8 L / ~5 kg) for repairs, single small rooms, anchor holes. 3.5 gal (13 L / ~17 kg) for mid-size rooms. 4.5 gal (17 L / ~20 kg) standard contractor SKU at some retailers. 5 gal (19 L / ~25 kg) the contractor default. Covers ~700-800 sq ft of Level 4 finish, about $15-20 each at big-box, lasts 6 months unopened. Metric SKUs sold in AU/UK/EU: 5 / 17 / 20 / 25 kg buckets, with 20 kg as the contractor default. Switch the calculator to Metric in the unit selector to pick from kg buckets directly.

Yes. Pick Metric in the unit selector at the top. Direct area input switches to m². Room dimensions input switches to meters. Mud weight outputs in kg (1 lb = 0.454 kg). Gallons stay in gallons since joint compound is sold by the gallon globally (1 gal = 3.79 L). Coverage rates display per m² in the reference table. Common conversions: 500 sq ft = 46 m², 1 lb/sq ft = 4.88 kg/m². Your unit choice sticks across pages via localStorage.