油漆计算器 — 估算任意房间所需加仑数 & 覆盖面积
输入房间的长度、宽度和天花板高度以及门窗数量。计算器扣除标准开口面积后乘以涂刷遍数，再除以油漆覆盖率，给出所需的精确加仑数和夸脱数——无需猜测。
Paint Calculator
Estimate gallons and quarts needed to paint any room
Room Dimensions (feet)
Openings (subtracted from wall area)
21 sq ft each
15 sq ft each
Number of Coats
Standard latex paint: 350 sq ft/gal. Premium or thick paint: 250–300 sq ft/gal.
Frequently Asked Questions
如何计算房间需要多少油漆？
将房间周长（2×长+2×宽）乘以层高得到总墙面积，减去门窗面积（门约1.8m²，窗约1.2m²），再除以油漆覆盖率（通常10-12m²/升）即可。例如4m×5m、2.7m高的房间：墙面积 = (4+5)×2×2.7 - 2门 - 2窗 ≈ 45m²，需约45/10 = 4.5升（单层）。
油漆每升能覆盖多大面积？
不同油漆覆盖率不同：普通乳胶漆10-12m²/升（单层）；高遮盖力漆12-15m²/升；底漆6-10m²/升（渗透性强）；外墙漆8-10m²/升；金属漆8-12m²/升。产品标签通常会注明理论覆盖率，实际覆盖率因底面颜色、表面粗糙度和施工方法约减少20-30%。
需要涂几遍油漆？
通常需要2遍正式漆（有时需要底漆+2遍面漆）：白墙刷深色：先1遍底漆，再2-3遍面漆；深色改浅色：1遍遮盖底漆，2遍浅色面漆；颜色变化不大：直接2遍面漆。质量要求高的场合（如商业空间）通常至少涂3遍以保证均匀度和耐久性。
天花板面积如何计算？
天花板面积 = 房间长度 × 宽度（平方米）。例如4m×5m房间天花板面积 = 20m²，需约20/10 = 2升油漆（单层）。若天花板有吊顶造型，需按实际面积计算。天花板通常需要2遍，使用专用天花板漆（流平性好、遮盖力强）。
油漆需要加水吗？
大多数乳胶漆不建议加水超过10%（稀释比例见产品说明）。适当加水可改善流平性，但过稀会降低遮盖力和最终漆膜厚度。底漆通常可稀释10-20%增加渗透性。溶剂型漆（调和漆）需加专用稀释剂，不可加水。第一遍可稍稀，第二遍用原液，以获得最佳效果。
房间油漆预算如何估算？
预算计算：确定总用漆量（升）；乘以所选品牌单价；加上工具费用（刷子、滚筒、遮蔽胶带等，约100-300元）；若请工人，人工费另计（约20-40元/m²，含材料价格因地而异）。自行施工可节省50-70%的总费用，但需要时间和技能准备。
新旧墙面在油漆用量上有何差别？
新建筑未刷过漆的墙面（水泥腻子）需先涂1-2遍渗透性底漆（用量约原墙的1.5倍），再涂面漆；旧漆面完好时，打磨清洁后可直接涂面漆2遍；旧漆脱落或有问题时，需刮除旧漆并重新做腻子。新旧墙面总用量差别可达50%，建议按新墙标准估算以留余量。
如何减少油漆浪费？
减少浪费的方法：使用计算器精确估算用量，多买5-10%作为补涂余量；选择合适的施工工具（平滑面用短毛辊，粗糙面用长毛辊）；避免滚筒沾漆过多（1/3-1/2浸入为宜）；剩余油漆密封保存（瓶口朝下或在表面覆保鲜膜防结皮）；乳胶漆密封后可保存1-2年。
Paint Calculator: Coverage, Coats & Gallons Guide
This paint calculator estimates how many gallons and quarts of paint are needed to cover the walls of a room. It deducts standard door and window areas from the total wall surface, then divides by your paint's coverage rate and the number of coats planned.
Paint Coverage Formula
Step 1 — Wall Area
The perimeter of the room multiplied by the ceiling height gives total wall area in square feet.
Step 2 — Deduct Openings
Standard door = 21 sq ft (3′ × 7′). Standard window = 15 sq ft (3′ × 5′).
Step 3 — Gallons
Result is rounded up to the nearest whole gallon.
Coverage by Paint Type
Coverage varies by sheen, brand, and substrate. Use these as starting estimates and check the label for the exact coverage rate.
| Paint Type / Sheen | Coverage (sq ft/gal) | Best For | Notes |
|---|---|---|---|
| Flat / Matte | 350–400 | Ceilings, low-traffic walls | Hides imperfections; hard to clean |
| Eggshell | 300–350 | Living rooms, bedrooms | Slight sheen; wipeable |
| Satin | 300–350 | Hallways, kids' rooms | Durable; shows brush marks |
| Semi-Gloss | 250–300 | Kitchens, bathrooms, trim | Washable; reflects light |
| Gloss / High-Gloss | 200–250 | Doors, cabinets, trim | Maximum durability; shows flaws |
Room Measuring Tips
- Measure each wall's length at the floor level and use the highest ceiling measurement for height.
- Round up fractional feet to the nearest half-foot for a safety buffer.
- For L-shaped or irregularly shaped rooms, break them into rectangles and add the wall areas.
- A standard interior door is 32–36 inches wide × 80 inches tall (≈ 21 sq ft).
- A standard double-hung window is 36 inches wide × 60 inches tall (≈ 15 sq ft).
- For large picture windows or sliding glass doors, increase the window count accordingly.
How Many Coats Do You Need?
1 coat
Refresh of same color, or when painting over a fresh primer that closely matches the finish color. Not recommended for color changes or new drywall.
2 coats (recommended)
Standard for most projects. Provides even, opaque coverage for color changes, medium-tone-to-light changes, and high-quality finishes.
3 coats
Needed when painting over very dark or saturated colors (deep red, navy, black), covering stains, or using a very light color over a dark substrate.
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