免费壁纸卷数计算器
计算房间所需的壁纸卷数，含图案对花余量。
Rolls Needed
8 rolls
Rolls Needed vs Room Perimeter
公式
## How to Calculate Wallpaper Rolls ### Formula **Net Wall Area = (Perimeter x Height) - Openings Area** **Usable Coverage per Roll = Roll Length x (Roll Width / 12) x Efficiency** **Rolls Needed = ceil(Net Wall Area / Usable Coverage per Roll)** Efficiency is typically 90% for solid or random patterns and 80% for patterns with a repeating motif. The repeat causes waste because each strip must be aligned to the pattern. ### Standard Roll Sizes American single rolls: 21 in wide x 33 ft long (about 57 sq ft gross). European rolls: 21 in wide x 33 ft long. Double rolls are twice the length.
计算示例
A room with 52 ft perimeter, 8 ft ceilings, 40 sq ft of openings, standard 21-inch rolls at 33 ft, no pattern repeat.
- 01Gross wall area = 52 x 8 = 416 sq ft
- 02Net area = 416 - 40 = 376 sq ft
- 03Coverage per roll = 33 x (21/12) x 0.90 = 51.97 sq ft
- 04Rolls needed = ceil(376 / 51.97) = 8 rolls
常见问题
What is a pattern repeat?
Pattern repeat is the vertical distance between identical points in the wallpaper design. A 21-inch repeat means the pattern repeats every 21 inches. Larger repeats produce more waste because strips must be aligned.
Should I buy single or double rolls?
Double rolls are twice the length of a single roll and waste less material since you get more full-height strips per roll. Most wallpaper is now sold in double rolls. Check the label for total square footage.
How do I account for windows and doors?
Measure the total area of all windows and doors and enter it as the openings area. A standard door is about 21 sq ft (3 ft x 7 ft) and a standard window is about 12 sq ft (3 ft x 4 ft).
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