Compound Miter Geometry calculator.
Find mathematical miter and bevel angles for a symmetric decorative corner from supplied corner and spring angles.
Your inputs
Schematic only. Use your measured dimensions and the stated angle convention.
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.
For a symmetric inside corner, define the spring angle from the vertical wall and the included corner angle between the walls. These formulas describe the geometric angles of a flat-laid decorative profile. They do not give machine setup, operating instructions, structural joinery requirements or tool suitability. Angles must lie strictly between 0 and 180 degrees for the corner and 0 and 90 degrees for the spring.
A worked example
Illustrative inputs only. Product properties and design dimensions are not recommendations for your project.
- Included wall corner angle
- 90 °
- Supplied molding spring angle from the wall
- 45 °
Geometric miter angle: 35.26 °
Symmetric inside corner; spring is measured from the vertical wall. Geometric angles only, not machine settings or operating instructions.
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.
Method: dimensional arithmetic and user-supplied specifications. Software checks: 2026-10-05. Calculation and review policy.