Calculating the miter angle for a joint is a fundamental woodworking skill. Here’s how to determine the correct angle for your project:

1. Identify the Total Corner Angle: For a regular polygon (like a square or hexagon), the corner angle is found with the formula `((n-2) * 180) / n`, where 'n' is the number of sides. For a custom corner, measure the angle directly using a protractor or angle finder.
2. Calculate the Miter Angle: The miter angle is always half of the total corner angle. This is because two pieces meet to form the corner, and each must be cut to an equal angle to create a symmetrical joint.
3. Determine the Saw Setting: Most miter saws are calibrated so that a 0° setting produces a 90° crosscut. Therefore, the angle you set on your saw is typically `90° - Miter Angle`. This calculator provides this "Saw Setting" for your convenience.

• Miter Angle: The angle to which each of two boards is cut in order to form a corner, typically half the total angle of the corner.
• Saw Setting Angle: The angle you physically set on your miter saw's scale. It is the complement of the miter angle (90° - miter angle).
• Corner Angle: The total angle of the corner you are trying to create. A square corner is 90°.
• Regular Polygon: A multi-sided shape where all sides and angles are equal (e.g., square, hexagon, octagon).
• Bevel Cut: An angled cut that goes through the thickness of the wood, as opposed to a miter cut which is across the face.

"The accuracy of your miter saw is paramount. Before starting a critical project, check your saw's calibration. Use a reliable square to ensure the 90° and 45° settings are perfect. Even a tiny discrepancy can lead to visible gaps in your joints. Also, remember that the numbers on the saw's scale are a guide; always perform a test cut on scrap pieces from the same stock to verify the fit before cutting your project pieces. This simple step can save you from costly mistakes and frustration." - Veteran Carpenter

Making a Hexagonal Box: A regular hexagon has 6 sides and interior angles of 120°. To create the box, you need to find the miter angle for each corner.
Calculation: `120° / 2 = 60°`.
Your saw setting would be `90° - 60° = 30°`. You would set your miter saw to 30° to cut the six pieces.

Fitting Trim into an Odd Corner: Imagine a wall corner that measures 130° instead of the standard 90°.
Calculation: `130° / 2 = 65°`.
Your saw setting would be `90° - 65° = 25°`. You would set your saw to 25° for both pieces of trim to create a perfect joint.

• Confusing Miter Angle and Saw Setting: Setting the miter angle directly on the saw is a common error. Always use the saw setting angle (90° - miter angle).
• Not Using an Angle Finder for Custom Angles: Assuming a corner is 90° when it's not is a frequent source of gappy joints in older homes.
• Blade Deflection: Pushing the saw through the wood too quickly can cause the blade to deflect, resulting in a slightly off-angle cut. Let the saw do the work.
• Wood Not Held Firmly: Ensure your workpiece is held securely against the saw's fence and table to prevent it from shifting during the cut.

• Picture Frames & Mirrors: The most common use, typically for 4-sided frames requiring 45° miter cuts.
• Trim and Molding: Essential for fitting baseboards, chair rails, and crown molding around corners.
• Custom Furniture: Building multi-sided tables, planters, or decorative boxes.
• Segmented Woodturning: Creating rings for bowls and vases by joining many small, precisely angled segments.