The cost to install an interior door lock is typically $75-$200 when replacing a standard knob or lever, including a basic lock and labor. A new hole in the door, a privacy or keyed lock, difficult hardware, and contractor minimum charges can raise the total.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Standard replacement | $75 | $125 | $200 | Existing hole and latch reused or replaced |
| New lock and door prep | $125 | $225 | $350 | Includes drilling or adjusting the door |
| Lock hardware | $10 | $35 | $150 | Basic knob through premium lever or smart lock |
| Labor or service minimum | $50 | $100 | $175 | May include travel or minimum billing |
What a standard interior lock installation costs
Replacing a passage knob or privacy lock usually costs $75-$200 per door. The average is about $125-$150 for a basic hardware set and a short installation using an existing bore and latch opening. A higher-end lever or a locksmith’s minimum charge can push the total toward the upper end.
Passage hardware has no locking function and is common on closets and hallways. Privacy knobs or levers, which lock from inside, generally cost a few dollars to several dozen dollars more. For a straightforward replacement, budget about $100-$175 per door before unusual door repairs.
Assumptions: Standard U.S. interior door, existing compatible bore, ordinary access, and basic to midrange hardware.
How hardware, labor, and door prep appear on a quote
Quotes may bundle labor and materials or list them separately. The table shows typical charges for one standard door; actual totals depend on the service provider’s minimum and whether the old hardware fits the replacement.
| Quote component | Typical price | What changes the charge |
|---|---|---|
| Basic lockset | $10-$40 per door | Finish, brand, privacy function |
| Midrange or premium lockset | $40-$150 per door | Lever design, durability, smart features |
| Installation labor | $50-$125 per door | Time, hourly rate, minimum charge |
| Door drilling or adjustment | $25-$100 per door | New bore, misaligned latch, oversized opening |
| Removal and disposal | $0-$30 per door | Often included for one old lock |
Handymen commonly charge $50-$100 per hour, while locksmiths may charge $75-$150 or more for a call-out or minimum service visit. A short job can therefore cost more than its actual hands-on time suggests.
Check whether the estimate includes the lockset, trip charge, door adjustment, and tax before comparing totals.
When a new bore or nonstandard door raises the price
Using the existing 2⅛-inch bore and standard 2⅜- or 2¾-inch backset usually keeps installation simple. If the door has no bore, a contractor may charge $25-$100 extra to drill and align the hardware. New holes placed incorrectly can weaken or damage a door, so precise layout matters.
Solid-core doors, unusually thick doors, metal doors, and older doors with nonstandard dimensions can require specialized hardware or extra fitting. That can add $30-$150 or more, depending on the door and lock. A mortise lock generally costs more to fit than a standard cylindrical knob because its pocket must be cut into the door edge.
Confirm the door thickness and backset before buying hardware; a mismatch can turn a quick swap into a fitting job.
Which lock type changes the installation budget most
For most interior rooms, the choice between passage and privacy hardware is mainly a hardware-price difference. A basic privacy knob or lever often costs $15-$60, while decorative or heavy-duty models may run $60-$150. A keyed lock on an interior door may cost $20-$100 for the hardware, with installation priced similarly to a standard replacement if the bore matches.
Smart locks are less common on interior doors. Models may cost $80-$250, and fitting can add $75-$175 if the lock is compatible with the door and existing preparation. Extra setup, connectivity equipment, or door modifications can increase the bill. For a bedroom or bathroom, a standard privacy set is usually the lower-cost option.
How long the installer needs and what minimums mean
A compatible lock replacement often takes 20-45 minutes per door. Drilling a new bore, correcting a crooked latch, or adapting older hardware can extend the work to 1-2 hours. For a single door, the billed amount may reflect a minimum visit rather than only the time spent installing the lock.
For several doors, ask whether the installer charges a separate labor rate per lock or a single service minimum plus an added per-door fee. Bundled work may reduce the effective labor cost, especially when all doors are accessible and use the same type of hardware.
For one lock, compare the full minimum charge; for multiple doors, compare the total project price.
Three realistic interior lock installation estimates
These examples assume ordinary residential access and typical U.S. labor rates. Local quotes can differ, and repair needs may change the scope.
| Job scope | Hardware | Labor and prep | Estimated total |
|---|---|---|---|
| One bedroom lock swap | $25 privacy knob | 0.5 hour at $90 per hour plus $45 minimum/travel | $115-$150 |
| Three matching privacy levers | $35 each, $105 total | 1.5 hours at $85 per hour | $220-$260 |
| One new bore and premium lever | $95 lever | 1.5 hours at $100 per hour plus $50 drilling | $275-$325 |
The example totals may exclude sales tax or door repairs. Quotes should state whether the old lock is removed, whether the latch is included, and what happens if the new hardware does not fit.
Use the same lock type and number of doors when requesting estimates so the totals are comparable.
Ways to lower the cost without compromising fit
Keep the existing bore and backset when possible, and choose hardware designed for the door’s thickness. Buying a standard lockset yourself may reduce material cost, but confirm the installer will fit customer-supplied hardware and whether a warranty applies to it.
Combine several lock replacements into one visit to spread any service minimum across more doors. Remove personal items near the work area and identify which doors need privacy locks, passage knobs, or keyed access before the appointment. Avoid paying for decorative or smart features that do not meet the room’s actual needs.
The biggest controllable savings usually come from avoiding unnecessary drilling and bundling compatible doors into one visit.