Drywall Calculator
Estimate how many drywall sheets you need for walls, ceiling, or both. Deduct openings and add a waste factor for accurate purchasing.
Measurements
Results
Fill in your measurements and click Calculate to see results.
How to Use This Calculator
Select whether you need drywall for walls, ceiling, or both. Choose how you'd like to enter your measurements — by room perimeter, individual wall dimensions, or a total area you've already calculated.
Enter any openings (doors, windows, archways) to be deducted. Standard drywall sheets in the US measure 4×8 ft (32 sq ft), though 4×10 and 4×12 sheets are common for rooms with higher ceilings.
A 10% waste factor is recommended for most rooms. Increase it to 15–20% for rooms with complex angles, vaulted ceilings, or many cuts around openings.
Tips for Buying Drywall
Always round up to the nearest whole sheet — you can't buy fractions. Buy a few extra sheets to cover damage during transport or installation. ½-inch drywall is standard for interior walls; ⅝-inch is used for ceilings and fire-rated assemblies.