Cornice Calculator
Enter the room perimeter, cornice width and thickness to calculate the total cornice length and volume for accurate material estimation.
Input Data
Results
At a glance:A cornice runs along the junction of the ceiling and wall. Total length = perimeter × (1 + waste%), where waste covers corner joints and cutting (8–12%). Volume = total length × width × thickness (converted to metres); weight = volume × material density. Plaster cornices are heavy while PU cornices are light, which affects handling and support. This calculator covers the moulding volume only and excludes adhesive and fixings.
Formula
Total length = perimeter × (1 + waste%)
Volume = total length × width × thickness
Weight = volume × density
$$L = P(1+w)$$$$V = L \cdot b \cdot t$$$$M = V \cdot \rho$$How to Use
- Measure the total ceiling-line length of the room (perimeter).
- Enter the cornice width and thickness (mm).
- Set the waste percentage and material density.
- The tool outputs total length, volume and weight.
Case Studies
Plaster cornice in living/dining room
Perimeter 16 m, width 100 mm, thickness 20 mm, waste 8%, plaster 900.
Total length 17.28 m; volume 0.03456 m³; weight about 31.1 kg.
PU cornice in bedroom
Perimeter 14 m, width 75 mm, thickness 15 mm, waste 10%, PU 150.
Total length 15.4 m; volume 0.0173 m³; weight about 2.6 kg.
FAQ
Is the cornice calculation the same as for skirting?
Both use perimeter × waste then multiply by cross-section, but cornices are usually wider and thicker with slightly higher waste; the weight difference comes from material density.
Why is PU cornice light?
PU (polyurethane foam) has very low density (about 100–200 kg/m³), making it easy to handle and friendly to older building ceilings.
Related Tools
References
Content review: Calculatorism Editorial Team. Results are for reference only; please refer to the relevant authorities for the official figures.