Stock lengths, corner treatment, fasteners and cost for any room's crown run.
Estimates are planning aids, not a professional quote. Double-check quantities and product coverage — and any local code or permit requirements — before you buy.
| Siding & Trim | $97–$131 |
| Fasteners & Hardware | $28–$37 |
| Finishing & Sealant | $19–$25 |
| Total | $143–$194 |
Excludes tools, delivery, tax and permit fees. Labor not included — this is a DIY materials estimate.
These are affiliate links: we may earn a commission if you buy through them, at no extra cost to you. It never changes what the calculator recommends — the shopping list comes from your dimensions, not from what pays.
About this calculator
Enter your room's length and width, how many inside and outside corners it has, and whether you're coping or mitering the inside joints, and the Crown Molding Calculator returns exactly how many stock lengths to buy, plus nails or clips, adhesive, caulk and filler — with a waste allowance sized to your corner count and joint method. It also gives a realistic build time and difficulty rating.
Crown sits at an angle instead of flat against the wall, so it cuts differently than baseboard or casing — either nested at its spring angle on a compound miter saw or laid flat with a compound bevel-and-miter setting. Pick a profile size and material and the takeoff updates instantly, whether it's primed MDF for paint or hardwood for a stain-grade room.
Step by step
A step-by-step walkthrough to go with your plan above. Follow the product instructions and any local code or permit requirements as you work.
Walk the perimeter, count inside and outside corners, and pick a profile size and material based on the room's ceiling height and whether it's paint or stain grade. Bigger profiles suit taller ceilings; keep it modest under 8 ft so it doesn't crowd the room.
Check the profile's spec sheet or test a scrap for its spring angle — 38° and 45° are the two common ones, each with its own miter saw chart. Decide whether you'll cut nested (upside-down at the spring angle) or flat with compound settings, and stick with one method for the whole room.
Start on the longest wall opposite the entry with square-cut ends that butt into the corners on both sides. Getting this piece dead straight and tight gives every coped piece after it a clean edge to register against.
Cut the next piece square, then back-cut along its profile line with a coping saw at a slight back-bevel so only the front edge touches. Test-fit against the installed piece and pare the cut with a utility knife until the profiles nest with no gap.
Cut matching 45° miters on both pieces meeting at an outside corner, glue the joint, and pin it with a finish nail so it can't open up. Outside corners are mitered regardless of how you're treating the inside ones.
Run a stud finder along the top of the wall to mark the plate and studs, then nail the top and bottom edges into framing and lay a bead of construction adhesive behind the piece for full contact. Switch to clips instead if you're mounting over drywall alone.
Set nail heads and fill them, then run a thin bead of paintable caulk along every seam, coped joint and the wall/ceiling reveal to hide small gaps. Let it skin over before sanding lightly for paint.
Stand across the room and check the run at eye level for gaps or a wavy reveal line, touching up caulk or filler wherever it catches the light. A tight-looking corner up close can still show a shadow line from across the room.
Equip the job
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Keep planning
Interior & Finishing
Answers
Measure the room's perimeter — twice the length plus twice the width for a rectangle — then add extra for waste and corner cuts. This calculator adds roughly 10% waste plus a small allowance per corner (more for coped joints, which take a few trial cuts to fit tight), then rounds up to whole stock lengths. A typical 12×14 bedroom with four coped inside corners runs about five 12-foot sticks.
Pros generally cope inside corners and miter outside ones. Walls are almost never exactly 90 degrees, and a mitered inside joint opens a visible gap as lumber and framing move with the seasons — a coped joint, where one piece is cut to the profile of the other and slides behind it, stays tight even as the angle shifts slightly. Coping takes more practice with a coping saw, but it's the durable choice; mitering both corners is faster and fine for a quick, low-visibility job.
Spring angle is the angle the molding's back sits away from the wall and ceiling — almost always 38 or 45 degrees depending on the profile. You cut it two ways: 'nested,' tilted upside-down in the saw at its spring angle with simple miter cuts, or laid flat against the fence using a compound bevel-and-miter setting specific to that spring angle. Mixing settings from a 38° chart onto 45° crown throws every joint off, so confirm your profile's angle before cutting.
Ideally yes — crown holds best nailed into the top plate along the ceiling and into studs along the wall, which is why installers sometimes add blocking behind drywall-only corners or vaulted transitions before hanging it. Where there's no backing to hit, molding clips (screwed to the wall or ceiling framing at intervals) or a generous bead of construction adhesive can carry crown on its own — this calculator swaps in clips when you select that mounting option.
Yes, and for most painted rooms it's the easier, cheaper choice. Polyurethane foam is lightweight, won't shrink or split, and coped or mitered corners forgive small gaps that filler or caulk hides completely. Primed MDF and finger-joint pine cost less than foam and cut like wood but need caulking at every seam. Save solid hardwood for a stain-grade room where the profile stays natural — filler and caulk show through a clear finish.