Walk into any home center and you will see two big bins of interior doors: one stacked with bare panels, one with doors hanging in full frames. The prehung vs slab door decision comes down to three things: whether you already have a solid jamb, how confident you are with a level and shims, and how much you want to spend. Pick wrong and you will either pay double for labor or fight a door that never latches right. This guide breaks down what separates the two, where each one wins, and the real numbers behind both choices.
What Is a Prehung Door
A prehung door is a complete unit. You get the door slab already hinged inside a three-sided jamb, with the strike plate mortised and the hinges pre-drilled. Most prehung doors ship with the doorstop molding attached, and many include the bore hole for a standard 2-3/8-inch backset knob.
The appeal is obvious: you drop the unit in the rough opening, shim it plumb, and nail it off. No chisel work, no mortising, no guessing whether your new slab will swing true. For a homeowner installing a door for the first time, prehung cuts the learning curve in half.
What Is a Slab Door
A slab door is just the panel. No jamb, no hinges, no bore. You are buying the wood (or MDF, or composite) and nothing else. Slab doors make sense when you already have a jamb that is plumb, square, and in good shape. In that case, replacing a beat-up door means pulling the old one off the hinges, matching the hinge mortises on the new slab, drilling the knob bore, and rehanging.
That is more work than it sounds. Transferring three hinge locations and a bore hole without a jig is how DIYers end up with doors that rub, latch high, or swing open on their own.
Cost Comparison
Pricing varies by material, but the spread is consistent across brands like Masonite, JELD-WEN, and Reliabilt.
- Hollow-core slab: $30 to $60
- Hollow-core prehung: $90 to $160
- Solid-core slab: $80 to $180
- Solid-core prehung: $180 to $320
- Solid wood slab (oak, maple): $200 to $500
- Solid wood prehung: $400 to $900
Prehung doors cost roughly double the slab, but you are paying for the jamb lumber, the pre-hung labor at the factory, and usually the casing package if you buy the “complete” SKU. The premium starts to pay off once you factor in the three hours of carpentry a slab swap can eat.
Install Difficulty
This is where the prehung vs slab door question really lives. Swapping a slab into an existing jamb sounds simple until you realize the old jamb has settled, the hinges are sagging, and the new slab is 1/8 inch thicker than the old one.
Slab door steps
- Remove the old door and measure height, width, thickness, and hinge spacing.
- Trim the new slab to size with a circular saw and a straightedge, leaving 1/8-inch gaps on the sides and top and a 1/2-inch gap at the bottom for carpet.
- Transfer hinge locations with a combination square and mortise with a chisel or router jig (a Porter-Cable 59381 template runs $80).
- Drill the knob bore and latch bore with a 2-1/8-inch hole saw and a 1-inch spade bit.
- Hang and adjust.
Prehung door steps
- Remove the old casing and door unit.
- Drop the new unit into the rough opening.
- Shim the hinge side plumb, nail through the jamb into the king stud.
- Shim the latch side, check for an even reveal, and nail.
- Install casing and set the knob.
A handy homeowner can install a prehung in 45 minutes. A slab swap takes two to four hours the first time.
When a Slab Door Wins
Slab is the right call when the existing jamb and casing are in good shape, square, and stained or painted to match the rest of the trim. Ripping out a perfectly good oak jamb just to install a prehung is a waste of money and creates drywall repair you did not need.
Slab also wins for custom sizes. If your 1920s home has a 29-1/2-inch wide opening, you are not finding a prehung in that dimension at Home Depot. You buy a stock slab and trim it to fit.
When a Prehung Door Wins
Prehung is the right call for new construction, full remodels, and any situation where the existing jamb is racked, rotted, or missing. If the door sticks no matter how much you plane the slab, the jamb itself is out of plumb, and no amount of new slab will fix it.
Prehung is also the answer when you want to upgrade from hollow-core to solid-core for sound control. Solid-core slabs weigh 60 to 80 pounds, and hanging them on old hinges in an old jamb rarely ends well. A new prehung unit comes with hinges rated for the weight.
Common Pitfalls to Avoid
Whichever route you take, these mistakes show up again and again.
- Forgetting to account for flooring. Measure from finished floor, not subfloor, or the door will drag on new carpet or LVP.
- Skipping the shims behind the hinges. Without backing, hinge screws pull out and the door sags.
- Using 1-inch trim nails in the jamb. Use 2-1/2-inch finish nails into the framing, not just the jamb.
- Ignoring the swing direction. A left-hand inswing and a right-hand inswing are not interchangeable.
- Buying a slab without checking jamb depth. Standard jamb is 4-9/16 inches for 2×4 walls, 6-9/16 inches for 2×6.
Bottom Line
For most remodels with sound existing jambs, a slab door saves money and matches the original trim. For new openings, damaged jambs, or a first-time installer, a prehung door is almost always worth the extra $100 to $200. The prehung vs slab door choice is not about which is better in the abstract, it is about what your opening already has and what tools you own.
