Dial in crown, base, and casing joints fast. Get miter and bevel settings with clear direction. Save results as exports for jobsite notes today.
| Corner angle (deg) | Spring angle (deg) | Miter (deg) | Bevel (deg) | Typical use |
|---|---|---|---|---|
| 90 | 38 | ≈ 31.62 | ≈ 33.86 | Crown molding inside corner |
| 90 | 45 | ≈ 35.26 | ≈ 30.00 | Common 45° spring profiles |
| 135 | 38 | ≈ 16.62 | ≈ 37.39 | Open corner / bay conditions |
Values are approximate and depend on the selected profile and field measurement accuracy.
This calculator uses standard compound miter relationships for crown and trim installed at a spring angle.
Let C be the included corner angle, and S be the spring angle.
miter = atan( sin(S) / tan(C/2) )bevel = asin( cos(S) * cos(C/2) )Angles are computed in radians internally, then converted to degrees for display.
Measure carefully, cut once, and verify fit before fastening.
Compound cuts appear when a profile meets a corner while held at a spring angle, like crown moulding, fascia returns, or boxed beams. A simple 45° miter rarely fits because the stock is rotated and tilted in two planes. Correct angles reduce gaps, save filler time, and keep assemblies square.
The included corner angle is the angle between two walls or members. Inside corners are often near 90°, but renovation work can vary several degrees. The spring angle is the profile’s installation angle relative to wall or ceiling, commonly 38° or 45°. Accurate measurement beats extra decimals. For outside corners, keep magnitudes but reverse orientation.
The tool returns saw miter (table rotation) and saw bevel (blade tilt) needed for the joint. It can also show “nested” equivalents for setups where the work is held against the fence. Confirm left/right and inside/outside orientation for your saw before cutting. Some crews label results as left-hand and right-hand cuts to prevent swapping pieces mid-install.
Miter changes the cut in plan view; bevel changes it in elevation. Steeper spring angles or out-of-square corners typically push the bevel higher. When a corner opens wider, miter often decreases while bevel increases, helping the cut wrap cleanly around the corner.
Drywall buildup, framing twist, and material cupping affect fit. Capture the actual corner with an angle finder, then cut short test pieces. Tight at the heel but open at the toe suggests a small miter tweak; a uniform face gap points to bevel. Record final settings per location. Adjust in steps; one degree can change the joint line dramatically.
Use this for crown on vaulted ceilings, outside corners on window heads, handrail returns, column wraps, and soffit trims. In roof carpentry, compound angles show up at hip and valley intersections where members meet at different pitches. Keep one reference face to avoid mirrored mistakes.
Exporting CSV helps store corner location, measured angle, spring angle, and final saw settings. Print the PDF for the site folder so crews can match left/right pieces, note bevel direction, and track which corners were measured rather than assumed. Consistent rounding prevents crew mix-ups.
Lock detents, verify the bevel scale, and support long stock so it cannot roll. Keep hands clear of the blade path when changing bevel. Mark the profile’s top edge and wall edge, then dry-fit before committing to production cuts.
A compound miter combines a miter angle and a bevel angle so the cut works in two planes. It’s common for crown, trim returns, and any profile installed at a spring angle.
Measure the included angle where the pieces meet. Use the inside angle for inside corners. For outside corners, measure the outside included angle and keep your saw orientation consistent with your layout marks.
Use the spring angle specified by the crown profile, typically 38° or 45°. If unknown, place the crown in its installed position and measure the angle between the back face and the wall or ceiling.
Corners can be out of square, and stock can twist. Cut test pieces, then adjust miter for toe/heel gaps and bevel for uniform face gaps. Also confirm your saw’s bevel direction and scale accuracy.
Yes for finish elements that behave like a sprung profile meeting an included angle. For structural rafters, dedicated roof-framing calculators are better because pitch and plumb/seat cuts add constraints.
On most trim work, rounding to 0.1° is fine, but long runs amplify error. If the joint is critical, use higher precision, test-cut, and record the final tuned settings for that location.
Bevel direction depends on whether the piece is left/right and inside/outside. Mark the top edge and reference face, then mirror the setup for the opposite hand. Always confirm on scrap before production.
Confirm angles on scrap, then cut final pieces confidently.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.