Angle Cut Calculator

Precisely calculate miter, bevel, and compound cut angles for woodworking, metalworking, and construction projects

This free online tool helps you determine the exact miter and bevel angles needed for perfect joints between materials meeting at any angle. Whether you’re working on crown molding, picture frames, furniture, or metal fabrication, our calculator provides instant results with saw-setting instructions and material waste estimates.

Input Parameters

Calculation Results

Diagram will appear here
Miter Angle (Board A)
45.0°
Miter Angle (Board B)
45.0°

Saw Setting Instructions

Set your miter saw to 45.0° with no blade tilt

Why Accurate Angle Cuts Matter

Precise angle cuts are essential for professional-looking results in woodworking and metalworking. Inaccurate cuts lead to:

  • Gaps in joints that compromise structural integrity
  • Wasted materials from incorrect cuts
  • Time-consuming adjustments and refitting
  • Unsightly finished products with visible imperfections

How the Calculator Works

Our calculator uses trigonometric formulas to determine the exact miter and bevel angles needed for perfect joints. For standard miter cuts, the miter angle is simply half of the joint angle. For compound cuts with a bevel, we apply more complex 3D geometry calculations to account for both the miter and tilt angles.

Use-Cases & Examples

Example A: Skirting Board at a 135° Corner

For interior corners that aren’t standard 90° angles (common in bay windows), set the joint angle to 135°. The calculator will determine that each board needs a 67.5° miter cut.

Example B: Roof Brace at 30° Slope

When installing roof braces, set the joint angle to the angle between the roof and wall (typically 90°), then enable compound cut and set the bevel angle to the roof pitch (e.g., 30°).

Example C: Compound Cut for Sloped Ceiling

For crown molding on sloped ceilings, you need both miter and bevel angles. Set the joint angle to the corner angle (usually 90°), then set the bevel angle to match the ceiling slope.

Step-by-Step Guide for Using the Tool

  1. Measure the angle between the surfaces where your materials will meet
  2. Enter this angle in the “Joint Angle” field
  3. If working with non-standard corners, use the preset dropdown for common angles
  4. For material loss estimation, enter board dimensions in the advanced options
  5. For compound cuts (sloped surfaces), check the “Compound Cut” option and enter the slope angle
  6. Read the results and set your saw accordingly

Advanced Mode – Compound Cuts & Material Loss

Compound cuts involve both a miter angle (saw rotation) and a bevel angle (blade tilt). These are necessary when joining materials on non-horizontal surfaces, such as sloped ceilings or roof edges.

Material loss estimation helps you calculate how much length you’ll lose from your boards due to the angled cuts, allowing for better material planning and reduced waste.

Frequently Asked Questions

What’s the difference between miter and bevel?+

A miter cut is an angled cut across the face of a board, while a bevel cut is an angled cut through the thickness. A compound cut combines both.

Can I use this calculator for metal?+

Yes, the angle calculations are the same regardless of material. The calculator works for wood, metal, plastic, or any other material requiring angled cuts.

What if my saw uses left vs right tilt?+

The calculated angles remain the same, but you may need to adjust the direction of your cuts. Always make test cuts on scrap material first.

How accurate are the calculations?+

The calculations are mathematically precise. However, actual cut accuracy depends on your tools, measurement precision, and technique.