Miter saw guide
How to read a miter saw's two scales, where the common angles come from, the two ways to cut crown molding, and the safety rules the makers' manuals agree on. For any angle not shown here, use the miter and crown angle calculator.
Miter, bevel and compound cuts
A miter cut swings the blade left or right on the turntable; the scale reads 0° at a square crosscut. A bevel cut tilts the blade; that scale reads 0° with the blade upright. A compound cut uses both at once, which is what crown molding laid flat and the sloped sides of a box or hopper need. A single-bevel saw tilts one way only, so some compound cuts mean flipping the work end for end; a double-bevel saw tilts both ways.
Some odd-looking marks on a saw are crown settings. DeWALT's DWS779, for one, has a bevel stop at 33.9° for crown, per its manual:31.62° miter and 33.86° bevel are what 52/38 crown needs, laid flat, in a square corner.
Where the common angles come from
A frame with n equal sides is cut at 180° ÷ n on each end: 45° for a square frame, 30° for a hexagon, 22.5° for an octagon. Two boards meeting at any corner each take 90° minus half the corner angle, so a 135° bay-window corner is 22.5° on each piece. Some table saw miter gauges read 90° at square instead of 0°; on one of those, set 90° minus the angle. The polygon chart lists the common shapes.
Crown molding: nested or flat
Crown sits on the wall at a slant, its spring angle: about 38° from the wall for the common 52/38 profile, 45° for 45/45. There are two ways to cut it.
- Nested: the crown goes upside down, its flat back edges resting on the fence and the table, so it leans exactly as it will on the wall. Then only a miter is needed, 45° for a square corner, the same as flat stock. It needs a tall enough fence and blade capacity for the crown's width.
- Flat: the crown lies face up on the table. That fits wider crown under the blade, but the cut becomes a compound one: 31.62° miter with 33.86° bevel for 52/38 crown in a square corner.
A corner may not be exactly 90°. Measure the corner with an angle finder, enter it in the calculator, and cut a test pair from scrap before cutting the good stock.
Safety: what the manuals say
These are the rules the miter saw makers' own manuals state. Where three manuals agree it says so; where only two state a rule, both are named, and they may give different numbers. Your own saw's manual is the authority for your saw. The federal workplace rules for other machines are on the woodworking machine safety page.
Keep your hands and body out of the path of the blade.
Never run the saw without its guards in place and working.
Clamp the work to the fence and table; never hold by hand a piece too small to clamp.
Keep your hands well back from the blade: RIDGID says never within 3 in of the blade and its path, DeWALT no closer than 4 in (100 mm).
Let the blade stop turning before you raise the saw or move your hands.
Sources
- Makita, LS1216 Slide Compound Miter Saw instruction manual (safety rules; crown molding table A), read 2026-11-07
- RIDGID, R4121 12 in. Compound Miter Saw operator’s manual (safety rules; crown molding settings), read 2026-11-07
- DeWALT, DWS779 12" Double Bevel Sliding Compound Miter Saw instruction manual (additional safety rules; body and hand position), read 2026-11-07
Which size saw
Saws are named by blade diameter, usually 10 in or 12 in, and come as fixed (chop) saws or sliding saws whose head travels on rails to cut wider boards. How wide and how thick a board each one cuts at 90° and at 45° varies from model to model, and makers print it in different ways, some as inches and some as lumber sizes such as 2x6. So this guide gives no class figure: check the capacity table in the manual of the saw you are looking at against the widest board you plan to cut, at the angle you plan to cut it.