Joint Compound Calculator
Size your mud order from the number of drywall sheets and coats.
What you'll need to order
- all-purpose joint compound
- paper joint tape
- corner bead
- taping knives
- sanding sponge
Prices vary by region and haul distance. Get quotes from at least two local suppliers.
How this calculator works
gallons = sheets × 0.048 × coats
Setting-type compound in bags is measured by weight instead — roughly 0.4 lb per sheet per coat. Use setting compound for the tape coat and pre-mixed for the finish coats.
Switch the site to metric — the control is in the footer — and your inputs, your results and the tables below follow. The formula, the constants, the guidance text and the sources stay in US units on purpose: that is how the standards they come from are written, and restating them would detach each figure from the document you are meant to be able to check it against.
Where these numbers come from
- ASTM C475/C475M (Joint Compound and Joint Tape for Gypsum Board) 2022 — compound classification; consumption per sheet is a typical field figure
Check the edition. Codes are amended every few years, and the one your inspector works from may not be the one named above.
Worked example
With drywall sheets (4x8) 30 , number of coats 3 , this calculator returns 4.32 gal.
Joint compound for rooms of common size
Every row here opens the calculator already filled in. Copy that link and the numbers travel with it.
| Job | Size | Compound needed |
|---|---|---|
| Small bedroom | 14 × 3 | 2.02 gal |
| Main bedroom | 20 × 3 | 2.88 gal |
| Basement finish | 60 × 3 | 8.64 gal |
| Whole small house | 120 × 3 | 17.28 gal |
| Skim coat, level 5 finish | 30 × 4 | 5.76 gal |
Setting-type compound is sold by weight instead — roughly 0.4 lb per sheet per coat.
Frequently asked questions
How many buckets of mud do I need?
One 4.5 gallon bucket finishes about 30 sheets across three coats. Two buckets cover a typical whole-house job of 60 to 70 sheets, and a small room rarely needs more than a gallon.
How many coats of mud does drywall need?
Three for a standard level 4 finish: tape coat, fill coat and skim. A level 5 finish adds a full skim over the entire surface, which is worth it under gloss paint or raking light.
Should I use setting compound or pre-mixed?
Setting type, the powder you mix, for the tape coat and any deep fills — it hardens chemically, shrinks less and can be recoated in under an hour. Pre-mixed is easier to sand, so use it on the finish coats.
How much joint tape do I need?
About 40 linear feet per sheet of drywall. Paper tape is stronger and the right choice for flat and inside joints; mesh belongs only with setting compound.