Miter Saw Bevel Angle Calculator
Compound cuts need two settings: the miter (table swing) and the bevel (blade tilt). For crown laid flat, both come from the corner and spring angles - the working compound miter calculator returns the pair for any corner.
The two dials
For wall corner angle C and crown spring angle S, cutting flat on the table:
miter = atan( sin(S) / tan(C/2) ), bevel = asin( cos(S) * cos(C/2) )
The famous pair
A square corner with 38-degree spring crown gives the numbers stamped on most saws: miter 31.6, bevel 33.9.
Flat vs nested
Nested cutting (crown angled against the fence) needs only the miter swing - the working calculator covers both setups.
Frequently asked questions
Why does my 45-degree corner not cut at 45?
Real corners are rarely square. Measure the corner, halve it for the miter, and for sprung crown convert through the compound formulas - the calculator does this from the measured corner.
What are the 31.6/33.9 detents for?
They are the flat-cut settings for 38-degree spring crown on a true 90-degree corner - only correct for that spring angle and that corner.
Related pages
- Compound miter calculator - miter and bevel for crown and compound cuts.
- Miter angle calculator - plain (single-axis) miters.
- Trim & molding calculator - stock takeoff for the same job.