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Miter Angle Calculator
Calculate precise miter cutting angles for woodworking and carpentry projects
Precision
Accurate angles for perfect joints every time
Versatile
Works for any joint angle and board widths
Professional
Industry-standard calculations for quality work
Enter Joint Parameters
degrees
The angle where the two boards will meet (1° to 179°)
⚠️
Precision Critical
Accurate miter angles are essential for tight joints. Always test cuts on scrap material and verify measurements before cutting final pieces.
Miter Angle Results
JOINT TYPE
Right Angle (90°)
90° Total Angle
Board A Miter Angle
45.00°
Board B Miter Angle
45.00°
Miter Saw Settings
Board A Saw Angle
45.00°
Board B Saw Angle
45.00°
Set your miter saw to these angles (90° - miter angle)
Calculation Method
Equal width formula: Miter angle = Joint angle ÷ 2
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Understanding Miter Cuts and Angles
What is a Miter Cut?
A miter cut is an angled crosscut made across the width of a board. When two miter-cut pieces are joined, they form a corner at a specific angle. This technique is essential for creating picture frames, door trim, crown molding, and furniture.
Common Applications:
- • Picture and mirror frames
- • Door and window trim
- • Crown molding installation
- • Furniture construction
- • Decorative trim work
- • Box and case construction
Miter Angle Formulas
Equal Width Boards:
Miter Angle = Joint Angle ÷ 2
Different Widths (90°):
Angle A = arctan(width A ÷ width B)
Angle B = arctan(width B ÷ width A)
Miter Saw Setting:
Saw Angle = |90° - Miter Angle|
Key Concepts:
- Joint Angle: Total corner angle (θ)
- Miter Angle: Cut angle for each piece
- Saw Angle: Setting on miter saw
- Complementary: Saw angle + Miter angle = 90°
Common Joint Angles Reference
Rectangle/Square
90°
- • Picture frames
- • Window trim
- • Miter angle: 45°
- • Saw setting: 45°
Pentagon
108°
- • Decorative frames
- • Architectural details
- • Miter angle: 54°
- • Saw setting: 36°
Hexagon
120°
- • Table tops
- • Decorative trim
- • Miter angle: 60°
- • Saw setting: 30°
Octagon
135°
- • Stop signs
- • Window frames
- • Miter angle: 67.5°
- • Saw setting: 22.5°
Professional Cutting Techniques
Miter Saw Setup
- 1Calculate the miter saw angle using the formula: |90° - miter angle|
- 2Set the miter saw to the calculated angle
- 3Secure the workpiece against the fence
- 4Make a test cut on scrap material
- 5Verify the joint fit before cutting final pieces
Quality Tips
✓ Best Practices
- • Use a sharp, fine-tooth blade for clean cuts
- • Support long pieces with outfeed tables
- • Cut slightly long and trim to final length
- • Test joints on scrap material first
- • Keep saw blade perpendicular to fence
✗ Common Mistakes
- • Not accounting for blade thickness (kerf)
- • Cutting pieces in wrong direction
- • Not supporting the cut-off piece
- • Rushing through cuts without test pieces
- • Ignoring wood grain direction
Example: Picture Frame Calculation
Standard Picture Frame
Given:
- • Joint angle: 90° (square corner)
- • Frame material: Same width molding
- • Project: 8×10 inch picture frame
Calculation:
- 1. Miter angle = 90° ÷ 2 = 45°
- 2. Miter saw angle = |90° - 45°| = 45°
- 3. Set miter saw to 45°
- 4. Cut all four frame pieces at 45°
Result: Perfect 90° corners with 45° cuts
Hexagonal Planter Box
Given:
- • Joint angle: 120° (hexagon corner)
- • Material: Same width boards
- • Project: Garden planter
Calculation:
- 1. Miter angle = 120° ÷ 2 = 60°
- 2. Miter saw angle = |90° - 60°| = 30°
- 3. Set miter saw to 30°
- 4. Cut all six sides at 30°
Result: Perfect hexagonal shape with 60° cuts
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