Drywall Mud Calculator

Estimate how much joint compound you need to tape and finish a drywall job.

Mud Needed
— gallons
Joint compound.

Usage Tip

Use setting-type mud for the first taping coat on butt joints; it shrinks less and dries faster than pre-mix.

THE MATH
gallons = sheets × coats × 0.15
boxes = gallons ÷ 4.5 (pre-mix box)
Taping and finishing drywall takes several coats of joint compound. Mud use scales with the sheet count and the coats, and pre-mix comes in 4.5-gallon boxes.
Enter the number of 4×8 sheets and the number of coats (3 is standard, 4 for a smooth finish).
The estimate uses about 0.15 gallons per sheet per coat.
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The calculators and tools on Formula Factory are provided for general guidance and informational purposes only. Results are estimates based on standard formulas and the values you enter — they do not constitute professional engineering, electrical, or architectural advice. Always verify calculations with a qualified professional before making decisions for any safety-critical, code-compliance, or commercial application. Formula Factory makes no representations or warranties as to the accuracy or completeness of any result, and accepts no liability for errors, omissions, or any outcomes arising from reliance on this information.