How to Install a Deadbolt Lock
Add a deadbolt to your exterior door for better security, or replace an old one with a modern smart lock. This beginner project takes 30-45 minutes with basic tools.
Repair & Refinish Team
Published November 5, 2025 · Updated February 10, 2026
What You'll Need
- Drill with spade bit (2-1/8") and hole saw
- Chisel (1")
- Screwdriver
- Tape measure
- Pencil
- Utility knife
- Deadbolt lock set (or smart lock)
- Strike plate with screws (included)
- 3-inch screws (for strike plate reinforcement)
- Wood filler (if filling old holes)
Cost Estimate
Budget
$25
Mid-Range
$80
Premium
$250
A locksmith charges $100-$250 for deadbolt installation. A standard deadbolt costs $25-$50. A smart lock costs $150-$250.
Step-by-Step Instructions
Choose the Right Deadbolt
Step 1 of 7Measure your door thickness — standard is 1-3/8" or 1-3/4". Measure the backset (distance from the door edge to the center of the existing hole) — standard is 2-3/8" or 2-3/4". Buy a deadbolt that matches these measurements. For a new installation on a door without an existing deadbolt, the standard position is 6-12 inches above the existing knob.
Remove the Old Deadbolt (If Replacing)
Step 2 of 7Unscrew the two long screws on the interior side of the deadbolt. Pull the interior and exterior halves apart. Slide the bolt mechanism out of the edge bore hole. Remove the strike plate from the door frame. Clean out any debris from the holes.
Drill the Holes (New Installation Only)
Step 3 of 7Use the paper template included with the deadbolt to mark the hole positions. Drill the face hole with a 2-1/8" hole saw from one side until the pilot bit breaks through, then finish from the other side (this prevents splintering). Drill the edge hole with a 1" spade bit, boring straight into the edge to meet the face hole. Test-fit the bolt mechanism to confirm the holes align.
Drill the face hole from both sides to prevent splintering. If you drill all the way through from one side, the exit side will splinter badly.
Install the Bolt Mechanism
Step 4 of 7Insert the bolt assembly into the edge bore hole with the bolt faceplate flush against the door edge. Trace the faceplate outline with a pencil, then remove the bolt and chisel a shallow mortise (1/8" deep) so the faceplate sits flush. Reinstall the bolt and secure the faceplate with the provided screws. Extend and retract the bolt by hand to make sure it moves freely.
Mount the Lock Halves
Step 5 of 7Insert the exterior lock cylinder through the face hole, aligning the tailpiece (the flat bar) with the slot in the bolt mechanism. From inside, place the interior thumb-turn or keypad assembly over the mounting posts. Insert and tighten the two long connecting screws evenly — alternating sides to draw the halves together squarely. Don't overtighten or the lock will bind.
For smart locks, insert the batteries and run the setup app before mounting. It's easier to troubleshoot connectivity when the lock isn't on the door.
Install the Strike Plate
Step 6 of 7Close the door and mark where the bolt contacts the frame. Drill a 1" deep hole in the frame for the bolt to extend into. Chisel a mortise for the strike plate. Screw the strike plate to the frame using the provided screws PLUS one 3-inch screw that reaches into the wall framing. The short factory screws only grip the door jamb — a determined kick defeats them. A 3-inch screw into the stud makes the deadbolt truly secure.
The single most important step for door security: use at least one 3-inch screw in the strike plate. This anchors it to the structural framing, not just the thin door jamb.
Test and Adjust
Step 7 of 7Test the deadbolt from both sides. The bolt should extend and retract smoothly with the key and the thumb-turn. The bolt should slide into the strike plate without force when the door is closed. If the bolt doesn't align with the strike plate hole, file the plate opening larger or reposition the plate. Test with the door closed and locked — try pushing on the door to verify it's secure.
Recommended Products
ANSI Grade 1 security rating — the highest available for residential locks. Anti-pick shield, reinforced strike plate with 3" screws. Classic style, superior security.
Built-in WiFi — no hub required. Apple Home Key, Alexa, and Google compatible. Fingerprint-resistant touchscreen. Auto-lock. ANSI Grade 1 security.
Complete kit with 2-1/8" and 1" hole saws, mandrel, and guide template for drilling deadbolt and knob holes. Everything you need for a new lock installation.
Affiliate Disclosure: We earn a small commission when you buy through our links at no extra cost to you.
Tips & Warnings
- Replace the strike plate screws with 3-inch screws on every exterior door in your house. This $2 upgrade makes every door dramatically more kick-resistant.
- Smart locks with auto-lock features are ideal for families — the door locks itself after 30 seconds so you never wonder if you locked up.
- For maximum security, choose a deadbolt with an ANSI Grade 1 rating. Grade 1 is the highest residential standard and resists forced entry better than Grade 2 or 3.
- Keep a spare key in a lockbox or with a trusted neighbor — not under the mat or in a fake rock. Burglars know all the hiding spots.
- Never install a deadbolt that requires a key on the inside (double-cylinder) without checking local fire codes. Many jurisdictions prohibit them because they block emergency exit.
- If your door or frame is rotted or damaged, a new deadbolt won't provide security. Repair the structure first.
- Smart locks require battery replacement every 6-12 months. Set a calendar reminder so you're never locked out by dead batteries.
Frequently Asked Questions
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