Drywall Calculator
Estimate the drywall sheets, screws, joint compound, and tape your room needs.
Results are estimates for planning. Compound and tape amounts vary with finish level and technique. Order a little extra rather than risk a second trip.
How to Measure for Drywall
Drywall is estimated from the wall area, plus the ceiling if you're hanging it.
Walls and ceiling
Enter the room length, width, and ceiling height. Choose whether the ceiling is being drywalled too — it adds the floor-plan area to the total.
Openings and sheet size
Count the doors and windows so their area can be deducted, and pick your sheet size: 4×8 ft is easier to handle, 4×12 ft leaves fewer seams.
Common Mistakes to Avoid
- No waste factor. Cut-outs around outlets and odd corners create offcuts you can't reuse. Plan about 10% extra.
- Forgetting the ceiling. If you're drywalling the ceiling, make sure it's included — it's easy to leave out.
- Running short on compound. A three-coat finish uses more mud than people expect. Buy a full extra box.
- Ignoring sheet orientation. Hanging sheets the long way across studs reduces seams — plan the layout before buying.
Frequently Asked Questions
Add wall and ceiling area, subtract openings, divide by the sheet size (32 sq ft for 4×8, 48 for 4×12), and add ~10% waste.
4×12 sheets mean fewer seams to finish but are heavy; 4×8 sheets are easier for a DIY job in a smaller room.
A three-coat finish uses roughly 0.1-0.12 lb of all-purpose compound per sq ft of drywall.
About 32 per 4×8 wall sheet — one every 12 inches on the studs. Ceilings need closer spacing.
Yes. A door is about 21 sq ft and a window about 12 sq ft of wall that gets no drywall.