Crown Molding Angle Calculator
Miter and bevel for a compound cut from the corner and spring angles — the two formulas behind every chart — plus linear feet and sticks.
Miter and bevel for a compound cut from the corner angle and the crown’s spring angle — the two formulas behind every chart — plus the linear feet and sticks for the room.
| Miter angle (flat on the saw) | — |
|---|---|
| Bevel angle (blade tilt) | — |
| Nested cut instead | — |
| Linear feet | — |
| Sticks | — |
Two formulas, not a chart. With the crown lying flat on the saw, for a corner of C degrees and a spring angle S: miter = atan(sin S ÷ tan(C/2)), bevel = asin(cos S × cos(C/2)). For a square corner and 38° crown that is 31.6° and 33.9°; for 45° crown, 35.3° and 30°. Every chart is those two lines evaluated; the calculator evaluates them for the corner you measured, which is rarely 90.
The spring angle is on the back of the molding. It is the angle the crown leans off the wall — the two flats on the back are cut at 38/52 or 45/45 — and the profile does not tell you which. Set a piece against a square and read it, or measure the two flats; a 52/38 crown cut with 45/45 settings gaps at every corner.
Nested is the no-arithmetic way. Stand the crown upside down against the fence at its spring angle and cut a plain miter of half the corner angle — 45° for a square corner — with no bevel. The compound settings exist for saws and crowns too big to nest; the page prints both.
Inside and outside corners swap the direction, not the angles. The same miter and bevel serve both; which end of the stick is left and right, and which way the saw swings, is the part the chart never shows and a test cut on scrap always does.
Miter = atan(sin S ÷ tan(C ÷ 2)); bevel = asin(cos S × cos(C ÷ 2)), for crown cut flat; nested cut = C ÷ 2 miter, 0 bevel. Linear feet = perimeter × (1 + waste); sticks = ceil(linear feet ÷ stick length). Spring angles of 38° and 45° are the two common profiles; the corner angle is yours to measure.
Worked example
What miter and bevel for 38° crown in a square corner, cut flat on the saw?
- Miter = atan(sin 38° ÷ tan 45°) = atan(0.616) = 31.6°.
- Bevel = asin(cos 38° × cos 45°) = asin(0.557) = 33.9°.
- Nested against the fence instead: a plain 45° miter, no bevel. 44 ft of wall with 10% waste is five 12-ft sticks.
31.6° miter and 33.9° bevel — the chart values, from the two formulas that make every chart. For 45° crown it is 35.3° and 30°. Corners are rarely 90; measure yours and the page recomputes.
Questions
What angles do I set for crown molding in a 90° corner?
Cut flat, 38° crown: 31.6° miter and 33.9° bevel. 45° crown: 35.3° and 30°. Nested against the fence at its spring angle, either one is a plain 45° miter with no bevel.
What is the spring angle?
The angle the crown leans off the wall, cut into the flats on its back — 38/52 or 45/45 on most profiles. Read it off the molding; the wrong one gaps every corner.