Drywall calculator app: free sheet, mud and tape estimator (2026)

A drywall calculator app earns its place when it does more than divide square feet by 32. The supply house wants sheets by size, buckets of compound, rolls of tape and boxes of screws, and the customer wants a price. This guide covers what to look for, a worked room you can check any app against, and free options for Android, iPhone and the browser.

Short answer: on Android, Smart Drywall Calculator is free on Google Play (with ads) and works offline. On iPhone, the drywall calculator is part of Roofing Calculator & Estimator. In a browser, use the free drywall calculator at smartroofingcalculator.com.

What a good drywall calculator app should do

• Walls and ceilings separately. Ceilings often use a different board (½ in sag-resistant or ⅝ in) and longer sheets.
• Any sheet size. 4×8 is common for DIY; 4×12 means fewer butt joints and less taping for a crew.
• Openings deducted, with sense. Many hangers don't deduct small windows because the cut-out is waste anyway. You should be able to choose.
• Finishing materials in purchase units. Compound, tape, screws and corner bead, not just sheets.
• Room by room, rolled into a job. And a PDF or list you can send.
• Offline. New construction often has no Wi-Fi and weak signal.

A worked room you can check by hand

1. Room: 12 ft × 12 ft, 8 ft ceiling.
2. Walls: perimeter 48 ft × 8 ft = 384 sq ft. Ceiling: 12 × 12 = 144 sq ft. Total 528 sq ft.
3. 4×8 sheets cover 32 sq ft each: 528 ÷ 32 = 16.5, so 17 sheets before waste.
4. Add 10–15% for waste and breakage: about 19–20 sheets, before any deduction for the door.

If an app's answer is far off, check whether it included the ceiling and what waste it used. For a fuller walkthrough, including compound and tape, read how much drywall do I need.

Drywall options compared

What's in Smart Drywall Calculator

From its Google Play listing (checked October 3, 2026):

• a drywall and sheetrock calculator that gives sheets, joint compound, tape, screws and corner bead for a room, plus the installed cost per square foot;
• a Drywall Takeoff that draws each wall to scale, with sheet courses, butt joints, doors and windows;
• rooms rolled into a job, each with its own sheet size, thickness or finish level;
• pricing from your own price book and hang and finish rates, with markup and tax, and PDF export;
• 71 drywall tools, plus cement board and shiplap calculators; works offline.

On iPhone

We don't publish a separate drywall app on the App Store. The drywall calculators are inside Roofing Calculator & Estimator, alongside roof, deck, fence, insulation, tile, sod and gravel tools.

Spreadsheet and web options

The free web drywall calculator handles a quick count in any browser. For office estimating, the drywall takeoff workbook takes up to ten rooms and counts sheets in any size, screws per sheet, tape and compound. Insulating first? See how much insulation do I need.