Segmental Arch Opening Geometry calculator.
Combine a rectangular opening with a supplied minor circular arch to obtain face area and curved boundary length.
Your inputs
Use measurements from your plan and properties from your chosen product. Any prefilled values are illustrative.
A clear estimate starts here.
Enter your dimensions and product details to see the quantity and purchase breakdown.
Formula and assumptions
How this calculation works.
Combine a rectangular opening with a supplied minor circular arch to obtain face area and curved boundary length. No arch, lintel, support or window sizing recommendation.
A worked example
Illustrative inputs only. Product properties and design dimensions are not recommendations for your project.
- Opening chord width
- 2 m
- Rectangular part height
- 2 m
- Minor arch rise
- 1 m
Combined opening face area: 5.57 m²
Ideal supplied circular geometry, not an opening specification, fabrication template or structural arch design.
Before you purchase
Use dimensions from your plan and properties from your chosen product. Any design spacing, section or fixing pattern must already be specified.
No arch, lintel, support or window sizing recommendation.
Method: dimensional arithmetic and user-supplied specifications. Software checks: 2026-10-04. Calculation and review policy.