Background Calculator — Backdrop Panels & Print Size
Size backdrop panels and calculate print dimensions for your diorama background.
Adds 20mm where panels meet for gluing (one join on L, two on U). A single flat panel has no join, so nothing is added.
How We Calculate This
The calculator sizes your backdrop based on the base dimensions and your chosen shape (flat, L, U or curved).
Layout Calculations
- Flat: Width = base length (single panel, no join so no overlap)
- L-shape: Width = base length + base width + overlap
- U-shape: Width = base length + (2 x base width) + overlaps
- Curved: Width = depth ratio × approximate full perimeter of the base ellipse (default 0.75), where the perimeter is approximated as π × (length + width) ÷ 2
Frequently Asked Questions
Related Calculators
Base Size Calculator
Calculate the right diorama base dimensions for your subject and scale.
Terrain Calculator
Estimate plaster, foam and scenic materials for terrain features.
Vegetation Calculator
Plan static grass, foliage, tree and ground cover quantities for your scene.
Water Effect Calculator
Calculate resin, water effect and ripple product volumes for water features.
Lighting Calculator
Plan LED quantities, resistor values and power supply for diorama lighting.
Last updated: February 2026
All calculations are estimates. Always verify quantities before purchasing materials.