Published August 13, 2026 · Updated August 23, 2026 · By Tupep
Crown is measured at the ceiling, cut in the air
Crown molding does not sit flat against anything. It bridges wall and ceiling at an angle, so the corners eat material you did not plan for and the piece has to be held in the saw at that same angle or the joint will not close. The linear foot number is easy. Getting the right sticks in the truck is the part people get wrong.
Spring angle sets everything
Spring angle is how far the molding leans out from the wall. The two you will meet are 38/52 and 45/45. It is printed on the packaging, or measurable off the two flats on the back of the molding, which are the surfaces that register against the saw fence and table.
Spring angle plus molding width tells you two useful things: how far up the wall the crown rises, and how far out across the ceiling it projects. That projection is what an outside corner costs you.
| Molding width | Spring angle | Rise on wall | Projection on ceiling | Length added per outside corner |
|---|---|---|---|---|
| 3-5/8 in | 38/52 | 2-7/8 in | 2-1/4 in | 4-1/2 in |
| 4-1/4 in | 38/52 | 3-3/8 in | 2-5/8 in | 5-1/4 in |
| 5-1/4 in | 38/52 | 4-1/8 in | 3-1/4 in | 6-1/2 in |
| 4-5/8 in | 45/45 | 3-1/4 in | 3-1/4 in | 6-1/2 in |
At a 38/52 spring, rise is about 0.79 times the width and projection about 0.62 times the width. At 45/45 both are about 0.71 times the width. An outside corner adds the projection twice, once to each of the two pieces meeting there, because each one has to run past the corner to reach its long point.
The formula
Crown LF = ceiling perimeter + (outside corners x 2 x projection) + (number of cut ends x fitting allowance)
Fitting allowance is 2 in per end. That is not waste padding, it is the trial-cut budget. Almost no room is square, ceilings are rarely flat, and the standard method is to cut long, offer the piece up, and sneak up on the fit. If you cut to the exact measurement first time, you will be recutting from a shorter piece.
Worked example: 16 by 14 room with a chase
Take a 16 by 14 living room with a chimney chase projecting 1 ft 6 in into the room, 4 ft wide, centered on one of the 16 ft walls, and 3-5/8 in crown at 38/52.
The chase replaces 4 ft of that wall with 1.5 + 4 + 1.5 = 7 ft of surface. Ceiling perimeter is (16 + 14) x 2 = 60, minus 4, plus 7 = 63 ft. The chase creates two outside corners at its front face and two inside corners where its sides return to the wall, so the room has 6 inside and 2 outside corners, and it breaks into 8 pieces with 16 cut ends.
- Perimeter: 63 ft
- Outside corners: 2 x 2 x 2-1/4 in = 9 in, or 0.75 ft
- Fitting allowance: 16 ends x 2 in = 32 in, or 2.67 ft
- Total needed: 66.4 LF
Now buy it in sticks. Crown commonly comes in 8, 10, 12 and 16 ft.
| Piece | Wall length | Ends | Stock used |
|---|---|---|---|
| Wall A | 14 ft 0 in | cope both ends | 1 x 16 ft |
| Wall C | 14 ft 0 in | cope both ends | 1 x 16 ft |
| Wall D | 16 ft 0 in | cope both ends | 10 ft + 8 ft, scarfed |
| Wall B, left and right of chase | 6 ft 0 in each | cope both ends | 1 x 16 ft for both |
| Chase face | 4 ft 4-1/2 in long point | miter both ends | 1 x 8 ft |
| Chase sides | 1 ft 6 in each | cope and miter | from the 8 ft stick |
| Total purchased | 74 LF |
Seventy-four linear feet to install 63. Note the 16 ft wall: we did not buy a 16 ft stick for it. Once you trim the factory ends and leave a fitting allowance, a 16 ft stick will not produce a 16 ft piece, so that wall gets a scarf joint on purpose rather than by accident at 8 p.m.
Upside down and backwards
The reason crown gets cut nested, meaning upside down and backwards in the saw, is that a standard miter saw can only pivot in one plane. Holding the crown against the fence at its spring angle turns the saw into a model of the room: the fence is the wall and the table is the ceiling. Since the ceiling is above the crown in the room and the table is below it in the saw, the piece goes in flipped, and left-hand pieces get cut on the right of the blade. Set a stop block on the fence so every piece sits at exactly the same spring angle, because a degree of drift is a visible gap.
If you would rather use compound settings and lay the crown flat, the published numbers for a 90 degree corner are 31.6 degrees miter and 33.9 degrees bevel for 38/52 crown, and 35.26 miter with 30 bevel for 45/45.
Three things worth knowing before the first cut
- Cope your inside corners. Cut a 45 on the end, then cut the profile away along the line the miter reveals, back-cutting slightly. A coped joint absorbs a corner that is not 90 degrees and stays closed when the wood moves. Miters at inside corners open up.
- Check every corner with a bevel gauge. Drywall corners are commonly 88 to 93 degrees, not 90. Coped joints forgive that. Outside corners do not, so set those with a gauge and cut test blocks.
- Crown follows the ceiling, not a level line. If the ceiling sags, the crown sags with it, and it looks fine. Snap your line off the ceiling.
We add one full stick to any crown order over 50 ft. The cope that tears out on the last piece of the day is not a hypothetical.
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Sources and Further Reading
Run your own numbers with the Baseboard & Trim Calculator, or browse every tool on the calculators index. Coverage figures and material constants are cross-checked against manufacturer technical data sheets before publication. See our Methodology page for how figures are selected and verified.
Planning estimate only. Results assume standard conditions and are intended for material planning. Verify against your product’s technical data sheet and your local building code before purchasing. Structural, electrical, and gas work should be specified by a licensed professional.
Last updated: August 23, 2026
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