How to Replace Closet Doors Without Getting the Size Wrong

Disclosure: ClosetBlueprint is reader-supported. When you buy through links on our site, we may earn an affiliate commission at no extra cost to you. Learn more.

To replace closet doors, take the old doors and track out, measure the finished opening (width at the top, middle and bottom, height at the left, center and right), and buy a door or door kit made for the smallest of those numbers. Then hang the new track or hinges, set the door and adjust it until it closes evenly. If you keep the same type of door in the same size, it is usually an afternoon job with a drill, a level and a helper. Switching door types or resizing the opening is harder and costs more.

Below: each step, the measurements that trip people up, DIY closet door options that skip a new door, and what the job costs. If you haven’t picked a style yet, browse our 15 closet door ideas first.

In this guide

• Quick comparison: the five ways to replace a closet door
• Tools and supplies
• Step 1: Take out the old doors
• Step 2: Measure the opening (the step that decides everything)
• Step 3: Choose the door type
• Step 4: Buy the door and hardware
• Step 5: Install the new doors
• Step 6: Adjust and finish
• DIY closet doors: options that skip a new door
• How much it costs to replace closet doors
• Common mistakes to avoid
• FAQ
• The bottom line

Quick comparison: the five ways to replace a closet door

Most replacements fall into one of these paths. The first is by far the easiest.

Path	What you buy	Change the frame?	DIY difficulty	Relative cost
Same style, same size (bifold to bifold, slider to slider)	New panels, usually with a new track kit	No	Easy	$
Bifold to bypass sliding, or the reverse	New panels plus the other style’s track kit	No, if the opening is square	Easy to moderate	$ to $$
Bifold or slider to hinged or French doors	A prehung door or pair, with its own frame	Often: old jambs come out, opening may need resizing	Moderate to hard	$$ to $$$
Any door to a barn door	One oversized door and a wall-mounted rail kit	No, but the wall needs solid backing for the rail	Moderate	$$
Door to curtain	Rod or ceiling track plus curtain panels	No	Easy	$

Before you buy anything, check whether you need new doors at all. If the doors look fine but drag, jump the track or won’t close, the problem is often worn rollers, pivots or guides. A bifold door hardware kit or new bypass rollers cost far less than new panels.

Tools and supplies

• Tape measure, pencil and a 4-foot level (a 2-foot level works for bifolds)
• Drill/driver with bits, plus a stud finder if you are hanging a barn door
• Flat bar and hammer (only if trim comes off), wood shims for hinged doors
• A helper for lifting full-height panels, and two helpers for mirrored doors

Step 1: Take out the old doors

• Bifold doors: fold the pair closed, lift up so the bottom pivot clears its bracket, swing the bottom out of the opening and lower the door so the top pivot and guide slide out of the track. Then unscrew the track and the floor or jamb brackets.
• Bypass sliding doors: remove the floor guide first. Lift each panel up into the track, tilt the bottom toward you, and lower it out. Take the front panel out before the back one. Unscrew the double track from the header.
• Hinged doors: close the door partway, tap the hinge pins up and out with a nail set and lift the door off. If you are replacing the whole unit with a prehung door, the jambs and casing come out too (see Step 5).

Patch old screw holes and check that there is solid wood behind the header where the new track will go.

Step 2: Measure the opening (the step that decides everything)

A door half an inch too big won’t go in; one too small leaves gaps. Measure like this:

1. Width: measure the finished opening, jamb to jamb, at the top, middle and bottom. Use the smallest number.
2. Height: measure from the finished floor to the underside of the header at the left, center and right. Use the smallest number. Planning new flooring? Measure from its future surface.
3. Square: measure both diagonals, corner to corner. If they differ by more than about 1/4 inch, the opening is out of square.
4. Jamb depth and trim: note how deep the jamb is and whether trim sticks into the opening, because the track has to sit flat on the header.
5. Floor type: carpet, tile and wood take different floor brackets and guides.

Then match your numbers to how the door is sold:

• Bifold and bypass doors are sold by the finished opening they fit. A “36 x 80” bifold is meant for an opening of about that size; the panels themselves are a little smaller to leave room for the track and clearance. Fit ranges vary by brand, so read the sizing chart.
• Hinged slab doors are sold by the size of the door itself, so you need the size of the old door, not the opening.
• Prehung doors come with their own frame and are sold by door size, but they fit a rough opening (the framing behind the trim). A common rule of thumb is a rough opening about 2 inches wider and about 2 inches taller than the door, but follow the manufacturer’s number. You have to pull the trim to see it.

Sizes you’ll find most often at US home centers (stock varies by store):

Door type	Common stock widths	Common heights
Bifold, 2 panels	24, 30, 32, 36 in.	80 in. (96 in. in some styles)
Bifold, 4 panels	48, 60, 72 in.	80 in. (96 in. in some styles)
Bypass sliding (2 panels)	48, 60, 72 in.; wider sets use 3 panels	80 in. and 96 in.
Hinged slab or prehung, single	About 18 to 36 in., in 2-inch steps	80 in. (96 in. in some styles)
French pair (prehung)	About 48 to 72 in. total	80 in.

If your opening falls between sizes, you have three choices: buy the next size down and close the gap with trim, buy a slightly larger bifold and trim the panels (only a small amount; check the maker’s limit, since hollow-core doors have narrow solid edges), or order a custom size. Mirrored doors usually can’t be cut at all. For the depth and width of the closet behind the doors, see our guide to measuring your closet.

Step 3: Choose the door type

If the old door worked for the room, the same type is the cheapest, quickest route. If not, now is the time to switch:

• Bifold: opens almost the whole closet; needs about one panel width of floor in front.
• Bypass sliding: needs no floor space but only opens about half the closet at a time. Our sliding vs bifold closet doors comparison covers space, access and cost side by side.
• Hinged or French doors: seal the closet best and give a full view, but need clear swing space.
• Barn door: slides along the wall outside the opening, so you need bare wall beside the closet about as wide as the door. Our barn door closet guide has the sizing and rail lengths.
• Curtain: the cheapest and most renter-friendly fix, covered in our guide to closet door curtains.

Material matters as much as style. Hollow-core doors are light, cheap and easy to hang but dent easily. Solid-core and MDF doors block more sound but are heavier, so check the hardware weight rating. Mirrored and glass doors are the heaviest of all.

Step 4: Buy the door and hardware

Check what is in the box: many bifolds include the track and pivots, while some bypass panels are sold without track. Bypass kits are sold by opening width; rollers wear out first, so ball-bearing ones are worth it.

Paint primed doors flat on sawhorses before hanging. Plan the pulls too: bifolds need a knob or pull on each pair, and bypass doors need flush pulls so the panels can slide past each other.

Step 5: Install the new doors

Follow the instructions that come with your door, since pivot and roller designs vary. The general steps:

Installing bifold doors

1. Screw the track to the header, centered and level. Most kits have the track set a fixed distance back from the front edge of the jamb.
2. Fit the top pivot, bottom pivot and guide wheel to the door if they are not already installed.
3. Mount the bottom pivot bracket on the floor or the side jamb, directly below the top pivot position (use a level or plumb line).
4. Seat the top pivot and guide in the track, then lower the bottom pivot into its bracket.
5. Adjust the height so the door clears the floor, and the side position so it doesn’t rub the jamb. On four-panel doors, add aligners so the two pairs meet flat in the middle.

Installing bypass sliding doors

1. Screw the double track to the header, level along its whole length. Shim behind it if the header dips.
2. Attach the rollers to the top of each panel at the positions shown in the instructions.
3. Hang the back panel on the rear channel first, then the front panel on the front channel. Tilt each one in at the top and swing the bottom in.
4. Install the floor guide at the center, where the panels overlap, so both stay in line at the bottom.
5. Adjust the rollers until each panel hangs plumb, with an even gap at the floor and no gap at the sides when closed.

Installing a prehung hinged door

1. Cut the caulk and paint lines with a utility knife, pull the casing (trim) and take out the old jambs. Check the rough opening for size and plumb.
2. Set the new unit in the opening with the door closed, hinge side first. Shim behind the hinges until the hinge jamb is plumb, then nail through the jamb and shims.
3. Shim and nail the latch side and the head jamb, checking that the gap around the door stays even.
4. Open and close the door several times before you trim off the shims, then put the casing back or install new trim.

Hinged doors are the hardest of the three: a frame out of plumb makes the door swing open or shut on its own.

Step 6: Adjust and finish

• Close the doors and check that the gaps are even at the top, sides and center. Fine-tune with the adjusting screws on the pivots or rollers rather than moving the track.
• Fill old screw holes and nail holes, caulk the trim and touch up the paint.
• Dark closet? Add a motion sensor closet light.

DIY closet doors: options that skip a new door

If the old doors are solid and work, a makeover can be cheaper than replacing them:

• Paint and new pulls. A fresh color and modern hardware change plain flat doors more than you’d expect. Sand lightly, prime and use a durable enamel.
• Add trim to flat doors. Thin strips of wood or MDF glued and pinned to a flat door give it a shaker, board-and-batten or picture-frame look. Keep it thin on bypass doors so panels still pass.
• Peel-and-stick wallpaper on flat, smooth doors. It’s removable, which helps in rentals.
• Build a barn door from boards or a plywood panel and hang it on a store-bought rail kit. Buy the hardware first and build to its weight and thickness rating.
• Swap the doors for a curtain on a tension rod or ceiling track.

How much it costs to replace closet doors

Prices vary a lot by region, size and material, so check current prices at your local home center or on Amazon. What we can say:

• Doing it yourself: you pay for the door and hardware, plus paint and trim. Basic hollow-core bifolds and bypass panels in stock sizes are the cheapest; solid-core, glass and mirrored doors cost noticeably more.
• Hiring it out: Homewyse’s January 2026 estimate for one builder-grade 36 x 80-inch closet door, installed by a pro in an existing opening, is about $368 to $520 before local adjustment. Handoff’s national estimate is about $178 to $412 per door including materials and labor. Neither covers removal, framing changes or disposal; get local written quotes.
• What pushes the price up: wide openings (more panels or longer track), heavy materials, custom sizes, switching to hinged or French doors (new frames and trim), and any reframing to change the size of the opening.

The cheapest replacement is almost always the same style in a stock size, because nothing about the opening has to change. Call a pro if the opening must be resized, the header has no solid wood for a track, or you are hanging heavy mirrored panels without helpers.

Common mistakes to avoid

• Measuring the old door instead of the opening for bifold and bypass replacements. Those doors are sold by opening size.
• Skipping the weight rating on track and rollers, especially for mirrored, glass and solid-core doors.

New doors are a good time to rethink the inside too. Our free closet design tool lets you draw the closet to your measurements and plan rods, shelves and drawers around how the new doors open.

FAQ

Can I replace closet doors myself?

Yes, in most cases. Swapping bifold or bypass doors for the same style in the same size is a beginner-friendly project. Installing a prehung hinged door takes more skill, and changing the size of the opening is a framing job.

How long does it take to replace closet doors?

A same-style bifold or bypass swap is often done in an afternoon, not counting paint drying time. A prehung door with new trim takes longer.

Can you replace bifold doors with sliding doors?

Usually, if the opening is about 48 inches or wider. Remove the bifold track and brackets, patch the holes and install a bypass track kit sized for the opening. On narrower openings, each sliding panel would uncover only a small part of the closet.

Can bifold closet doors be cut down?

Only a little. Many hollow-core bifolds can be trimmed slightly at the bottom or edges, but the solid wood around the edges is narrow, so check the maker’s instructions for the limit. If you need to remove more than that, buy a smaller size or a custom door.

What size closet door do I need?

For bifold and bypass doors, measure the finished opening and buy the door made for that opening size. For a hinged slab, match the old door’s size. For a prehung door, measure the rough opening behind the trim and match it to the manufacturer’s chart.

The bottom line

Measure the opening in three places each way, use the smallest numbers, and buy the door sold for that opening. Keeping the same style is the easiest and cheapest route, switching between bifold and sliding is still a weekend project, and hinged or French doors mean new frames. If you’re still choosing a style, our closet door ideas lay out the options for every room and budget.

Shop the look on Amazon

Shoe storageRacks and shelves that end the pile on the floorShop on Amazon →

Slim velvet hangersMatching, space-saving hangers for every rodShop on Amazon →

As an Amazon Associate I earn from qualifying purchases.

Follow ClosetBlueprint for daily closet ideas

TikTok@closetblueprintPinterest@closetblueprint85