CalcCalculadora de Moldura de Teto
Última atualização: 2026-05-07
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| Comprimento do quarto (m) | Largura do quarto (m) | Comprimento de cada peça (m) | |
|---|---|---|---|
| Small door | 2.5 m | 2 m | 2.4 m |
| Standard door | 3.75 m | 3 m | 2.4 m |
| Large door | 5 m | 4 m | 2.4 m |
| Window | 7.5 m | 6 m | 2.4 m |
| Bay window | 10 m | 8 m | 2.4 m |
What is the Crown Molding Calculator?
Crown molding runs along the ceiling perimeter of a room, and ordering the right linear metres is critical — molding is sold in fixed lengths (typically 2.4 m or 3.6 m) and joins are visible if you use short off-cuts. This calculator computes the room perimeter, adds 10% for angled cuts and waste, and tells you how many lengths to buy.
You may also find the Baseboard Calculator, Decking Calculator, and Fence Picket Calculator useful.
Who Uses This Calculator?
This tool is used by homeowners installing crown molding, finish carpenters quoting trim jobs, and interior designers specifying millwork.
How to Use the Crown Molding Calculator
- Enter your Room length.
- Enter your Room width.
- Enter your Corner type.
- Enter your Molding piece length.
- Click Calculate to see your results instantly.
Formula
The calculator uses the following formula:
Perimeter = 2 × (length + width); Linear metres needed = perimeter × 1.1; Pieces = ceil(linear_m ÷ molding_length)
Worked Example
A 5 m × 4 m room with 90-degree corners requires 18 m of molding perimeter. Adding 10% waste gives 19.8 m — so buy 9 lengths of 2.4 m molding (21.6 m total).
Step-by-Step Calculation
- Room perimeter: 2 × (5 + 4) = 18 m
- Add 10% for mitre cuts and waste: 18 × 1.1 = 19.8 m
- Pieces of 2.4 m: ceil(19.8 ÷ 2.4) = 9 pieces
Common Mistakes to Avoid
- Not adding extra for mitre cuts — each inside corner wastes ~5 cm per piece
- Forgetting to measure the height at which crown contacts the wall and ceiling
- Ordering standard lengths without checking if longer pieces reduce waste
Frequently Asked Questions
Crown molding corners require compound mitre cuts — typically 45° mitre and 33.9° bevel for 90-degree inside/outside corners. A dedicated crown molding mitre setting on your saw makes this easier. Test cuts on scrap before cutting good stock.
10% is standard for rooms with 90-degree corners. Add 15–20% if the room has many corners or bay windows, since each corner requires angled cuts that waste material.
Crown molding should be nailed at 45 degrees into both the ceiling and wall — hitting studs and ceiling joists where possible. Use a stud finder first. Finish nails (50–65 mm) with a nail gun give the cleanest result.
Use paintable latex caulk, not silicone. Apply a thin bead along the top and bottom edges, smooth with a damp finger, and paint after it dries. Small gaps (< 3 mm) are expected and easily caulked.
Yes, but it requires raking crown molding that runs at the slope of the ceiling, not horizontal. The calculations are more complex. For dramatic vaults, consider cove molding which is more forgiving to install.