石膏板计算器
本石膏板计算器估算墙面所需石膏板数量以及配套耗材——螺丝、接缝胶带和腻子。输入墙面总长度和高度，指定门窗数量，选择标准 4×8 或 4×12 规格。适用于任意房间面积，即时得出结果。
Drywall Calculator
Enter your wall dimensions to estimate drywall sheets, screws, joint tape, and joint compound needed.
Each door ~21 sq ft
Each window ~15 sq ft
常见问题
石膏板计算器是如何工作的？
石膏板计算器根据房间面积计算所需石膏板数量。输入墙面或天花板的长宽尺寸，选择石膏板规格（通常为 4×8 ft 或 4×12 ft），计算器会自动计算所需数量并建议额外购买约 10% 的余量。
石膏板需要额外购买多少余量？
建议额外购买 10-15% 的余量，以应对切割损耗、错误和将来的修补需求。门窗开口不要从面积中扣除，因为小于 32 平方英尺的开口在施工中的损耗往往会抵消节省的材料。
我应该使用哪种厚度的石膏板？
墙面通常使用 1/2 英寸（12.7 mm）石膏板；天花板建议使用 5/8 英寸（15.9 mm）以防下垂；浴室区域应使用防潮型石膏板（绿板或蓝板）；防火分区需要使用 Type X 防火石膏板。
我还需要多少接缝带和泥浆？
接缝带用量约为石膏板接缝总长度（每张板约 16 英尺接缝）。泥浆用量通常为每 100 平方英尺墙面约 0.053 加仑。本计算器可提供接缝带和泥浆的估算用量。
How to Calculate Drywall: Complete Guide
Estimating drywall accurately before a project prevents costly over-ordering and frustrating mid-job shortages. This guide walks through the drywall formula, standard sheet sizes, supply estimates for screws, tape, and joint compound, installation tips, and how to account for doors and windows.
Contents
Drywall Formula
The number of drywall sheets required is calculated in three steps:
- Gross wall area = Wall Length × Wall Height
- Opening deductions = (Number of doors × 21 sq ft) + (Number of windows × 15 sq ft)
- Net area = Gross wall area − Opening deductions
- Sheets needed = ⌈Net area ÷ Sheet area⌉ (ceiling, always round up)
Example
Room perimeter: 44 ft · Height: 8 ft · 2 doors · 3 windows (4×8 sheets)
- Gross area = 44 × 8 = 352 sq ft
- Openings = (2 × 21) + (3 × 15) = 42 + 45 = 87 sq ft
- Net area = 352 − 87 = 265 sq ft
- Sheets = ⌈265 ÷ 32⌉ = ⌈8.28⌉ = 9 sheets
Standard Sheet Sizes
Drywall sheets come in two common residential sizes. Larger sheets reduce seams but are heavier and harder to handle alone.
| Sheet Size | Coverage | Best For | Weight (½″) |
|---|---|---|---|
| 4×8 ft | 32 sq ft | Standard 8 ft ceilings, one-person install | ~54 lbs |
| 4×12 ft | 48 sq ft | Fewer seams, tall walls, two-person crews | ~81 lbs |
Common thickness options: ¼″ (repair/curved walls), ⅜″ (remodel overlay), ½″ (standard walls), ⅝″ (fire-rated/ceilings).
Accounting for Doors and Windows
Openings reduce the amount of drywall required. Standard deduction values are:
Standard Door
3 ft × 7 ft = 21 sq ft
Based on a typical interior door opening (rough opening ~3½ ft wide).
Standard Window
3 ft × 5 ft = 15 sq ft
Based on a standard double-hung window. Adjust for larger or smaller windows.
Note: Many professional estimators do not deduct for small openings under 12 sq ft, since cut scraps are often too small to reuse. For large openings like sliding glass doors or picture windows, measure the actual rough opening.
Supply Estimates: Screws, Joint Tape, and Mud
Beyond the sheets themselves, every drywall job requires screws, paper joint tape, and joint compound (mud). Use these rule-of-thumb estimates:
Drywall Screws
Approximately 1 screw per square foot of net drywall area. Screws are placed every 8 inches along studs and 16 inches apart on edges. For a 265 sq ft job, expect roughly 265 screws — buy a box of 300.
Joint Tape
Approximately 12 linear feet of tape per sheet. Each sheet has 4 edges (two 8-ft sides + two 4-ft sides = 24 ft), but edges shared with adjacent sheets are taped once. 12 ft per sheet is a reliable estimate for paper tape.
Joint Compound (Mud)
Approximately 1 gallon per 100 square feet of net area for a 3-coat finish. Pre-mixed joint compound comes in 1-gallon, 3.5-gallon, and 4.5-gallon buckets. Lightweight all-purpose compound is easiest for DIYers; setting-type compound dries faster and is harder to sand.
Installation Tips
Hanging Order
- Hang ceilings first, then walls — ceiling sheets act as a ledge for wall sheets.
- Orient wall sheets horizontally (perpendicular to studs) to reduce butt joints.
- Stagger vertical joints between rows by at least one stud bay.
- Keep sheets ½″ off the floor to prevent moisture wicking.
Waste Factor
- Add 10–15% extra sheets for cuts, mistakes, and future repairs.
- Complex room shapes (angles, archways) need more waste allowance — up to 20%.
- Store extra sheets in the same room for color/batch matching on patches.
Finishing Coats
- Apply 3 coats: tape coat, filler coat, and finish coat. Sand between coats.
- Use corner bead on all outside corners before taping.
- Prime with drywall primer before painting to seal paper face and prevent flashing.