TL;DR: Replacing a door is a weekend project that can transform a room. You’ll need basic tools like a screwdriver, hammer, chisel, level, and saw. This guide covers everything from measuring and choosing the right door to hanging it perfectly, with cost estimates between $100 and $400.
What You’ll Need
Before you start, gather all the tools and materials. Here’s a complete list with estimated costs based on current Home Depot and Lowe’s pricing.
| Tool/Material | Purpose | Estimated Cost |
|---|---|---|
| Tape measure (25 ft) | Measure door and frame openings | $10–$20 |
| Pry bar (flat bar) | Remove old door and trim | $8–$15 |
| Hammer (16 oz) | Drive nails and chisel | $10–$20 |
| Screwdriver set (Phillips and flathead) | Remove hinges and hardware | $10–$25 |
| Level (4 ft) | Check door plumb and level | $15–$30 |
| Chisel (1-inch) | Mortise hinges | $8–$15 |
| Circular saw or handsaw | Trim door to size | $50–$120 (circular saw) or $15–$30 (handsaw) |
| Drill with bits | Pre-drill screw holes | $40–$100 |
| Shims (wood or plastic) | Level and plumb door in frame | $5–$10 per pack |
| Wood glue | Secure shims and repairs | $4–$8 |
| Safety glasses | Protect eyes from debris | $5–$10 |
| Work gloves | Protect hands | $10–$20 |
| New door (pre-hung or slab) | Replacement door | $100–$300 (interior) or $200–$400 (exterior) |
| Hinges (if not included) | Attach door to frame | $10–$30 per pair |
| Door handle/lock set | Function and security | $20–$80 |
| Finish nails (1.5–2 inch) | Secure casing trim | $5–$10 |
| Wood filler | Fill old screw holes | $5–$10 |
| Caulk and caulk gun | Seal gaps | $10–$20 |
Total estimated cost for tools and materials: $150–$400 (if you don’t already own basic tools). The door itself is the biggest expense.
How Long Does This Take?
This project takes about 4–6 hours for a first-timer. Here’s a breakdown by step:
- Step 1 (Measure and choose door): 30 minutes
- Step 2 (Remove old door): 45 minutes
- Step 3 (Prepare frame): 30 minutes
- Step 4 (Fit new door): 1–2 hours (most time-consuming)
- Step 5 (Install hinges and hardware): 1 hour
- Step 6 (Hang and adjust door): 1 hour
- Step 7 (Finish trim and seal): 30 minutes
Safety First
Always wear safety glasses and work gloves when cutting, prying, or hammering. Doors are heavy—get a helper to lift and carry them. Use a sturdy step stool or ladder if needed. Keep your work area clear of tripping hazards. If using power tools, read the manual and unplug them when changing blades.
Step-by-Step Instructions
-
Measure the existing door and frame opening.
Use a tape measure to get the width and height of the old door (measure from inside the frame, not the door itself). Also measure the rough opening (the stud frame behind the trim). Write these down. Interior doors are typically 30 or 32 inches wide, 80 inches tall. Measure twice to avoid buying the wrong size. Expect 15 minutes for this step. -
Choose your new door.
Decide between a pre-hung door (comes with frame, hinges, and pre-cut holes) or a slab door (just the door panel). Pre-hung is easier for beginners. Slab doors require cutting hinge mortises and drilling for hardware. For this guide, we’ll assume a pre-hung door. Buy a door that matches your rough opening measurements. Allow 15 minutes for selection. -
Remove the old door.
First, take off the door handle and lock set using a screwdriver. Then, remove the hinge pins by tapping them upward with a hammer and screwdriver. Lift the old door off the hinges and set it aside. Use a pry bar to carefully remove the casing trim around the door frame. Work slowly to avoid damaging the wall. Finally, remove the old frame by prying it away from the studs. Watch for nails and splinters. This step takes about 45 minutes. -
Prepare the rough opening.
Inspect the studs for damage. Use a level to check if the opening is plumb (vertical) and square. If it’s off by more than 1/4 inch, you may need to shim or adjust. Remove any old nails or debris. Clean the area so the new frame sits flat. This takes 30 minutes. -
Fit the new pre-hung door.
With a helper, lift the new door unit into the rough opening. The door should be slightly smaller than the opening. Place wood shims between the frame and the studs to adjust for level and plumb. Use a 4-foot level on the hinge side first. Check the top of the door for level too. Do not force the door—shim it gently. Once the frame is plumb and level, temporarily tack the frame in place with a few finish nails through the hinge side. This is the most critical step and takes 1–2 hours. -
Install hinges and hardware.
If your pre-hung door comes with hinges already attached, skip to the next step. Otherwise, mark the hinge locations on the door and frame. Use a chisel to cut shallow mortises for the hinges (about 1/8 inch deep). Screw the hinges into the door first, then the frame. For the handle, use the template that comes with the lock set to drill holes for the knob and latch. Install the latch mechanism and knob per the manufacturer’s instructions. This takes about 1 hour. -
Hang the door and adjust.
Swing the door open and closed to check for gaps. It should have about 1/8 inch gap on the sides and top, and 1/2 inch at the bottom. If the door sticks or rubs, adjust the shims or plane the edge slightly (use a block plane or sandpaper). Never plane more than 1/16 inch at a time. Once it swings smoothly, drive all the finish nails through the frame into the studs. Countersink the nails with a nail set. This takes about 1 hour. -
Install casing trim and seal.
Cut new casing trim to fit around the door frame (miter the corners at 45 degrees). Nail it in place with finish nails. Fill nail holes with wood filler and let dry. Apply caulk around the trim edges to seal gaps. Paint or stain the door and trim as desired. This final step takes 30 minutes.
Common Mistakes to Avoid
- Buying the wrong size door. Measure the rough opening, not the old door. A door that’s too big won’t fit; too small leaves ugly gaps.
- Skipping the level check. If the frame isn’t plumb and level, the door will sag or stick. Use a level at every stage.
- Over-tightening screws. This can strip the screw holes or crack the door frame. Tighten until snug, then stop.
- Forgetting to shim the latch side. The latch side needs shims too, or the door won’t close properly.
- Rushing the hinge mortises. If you cut mortises too deep, the hinges will sit crooked. Go shallow and test fit.
When to Call a Professional
Call a professional if:
- The rough opening is severely out of square (more than 1/2 inch difference in diagonal measurements).
- You’re replacing an exterior door with complex weatherproofing or security requirements.
- You find rot or structural damage in the studs or framing.
- You don’t own the necessary tools and don’t want to buy them.
- The door is heavy (e.g., solid wood or steel) and you don’t have a helper.
A professional door installer typically charges $150–$400 for labor, plus materials.
Frequently Asked Questions
Q: Can I reuse my old hinges and hardware?
A: Yes, if they’re in good condition. But new hardware is relatively cheap and ensures a better fit. For a pre-hung door, new hinges are usually included.
Q: What if my new door is too tall?
A: You can trim the bottom of a slab door with a circular saw. For a pre-hung door, you may need to cut the frame, which is more complex. Measure carefully to avoid this.
Q: Do I need to paint the door before hanging it?
A: It’s easier to paint a door while it’s flat on sawhorses. But if you hang it first, you can paint it in place. Both work; just protect the floor.
Q: How do I fix a door that sticks after installation?
A: Check the gap between the door and frame. If it’s tight in one spot, use a block plane or sandpaper to shave down the high area. Also check that the hinges are tight and the frame is still plumb.
Q: Can I install a door without a helper?
A: It’s risky. A standard interior door weighs 30–50 pounds. Use furniture dollies or straps to lift it, but a second person makes the job much safer and easier.
For more DIY projects, check out our guides on how to install a door frame, how to fix a sticking door, and how to replace door hardware. You might also like how to weatherproof an exterior door and how to paint a door like a pro.
