How Big Is A Deadbolt? [What Size Hole To Drill?]

You’ve purchased your deadbolt and are ready to install it. But now you need to figure out the size of the hole to drill. First, how big is the deadbolt? To help you answer these questions, we have done thorough research to come up with the best answer. 

Typical deadbolts require a hole of about 2 1/8 inches in diameter for the lock body and a spade bit that is 1 inch in diameter for the sliding bolt assembly. There is a template included in the deadbolt lock set that you can use to take the measurements of your deadbolt size and the hole to drill.

You may require a lock in a different size or thickness than the standard one, depending on the dimensions of your door. Keep reading to learn more about size calculations before installing a deadbolt lock. 

Dead bolt used by a locksmith - How Big Is A Deadbolt? [What Size Hole To Drill?]

Deadbolt Lock

Locksmith Installation Changing Door Locks

A deadbolt lock is the name given to a lock with a bolt that cannot be moved in any other way except by using a key or an access control system. This particular style of lock does not have a spring inside it. Compared to the weight and depth of a deadbolt lock, a typical spring latch is more slender and requires less effort to open. 

They can be made of steel or brass, and the very end of the lock does not have a rounded or angled tip as other locks do. One of the most dependable and cost-effective methods to strengthen the security of your home is to have a deadbolt lock installed in each of its outside doors.

When mounting the deadbolt, you have a lot of options. But you may not have much choice in where to place the lock if the door is situated in an awkward location.

Avoid loose fittings by following the recommended dimensions when installing the lock yourself. If your deadbolts are installed incorrectly, you may be putting your home in greater danger of burglary. If you're still unsure, talk to an expert.

How Big is a Deadbolt? 

There is a range of sizes available for deadbolts, with some companies offering them in sizes as small as 2 inches and as large as 5 inches. Deadbolts are commonly installed 6 to 12 inches above the key lock on most doors.

What Size of Hole Should I Drill For a Deadbolt? 

worker's hands installing new door locker man repairing the doorknob. closeup

The cross bore has a diameter of 2 1/8 inches for a deadbolt hole, and the latch bore needs a diameter of 1 inch. These are the standard measurements. You must use the appropriate diameter drill bits when drilling for the bores. If you have the appropriate drill bit, you won't need to measure the hole before creating it.

Are Deadbolts a Standard Size? 

Deadbolts come in many different sizes and this might be a little confusing. So are they all the same size, or do they vary depending on make and model?

Deadbolts are not standard is size. However, there is a simple way to figure out what size hole you should drill for your lock using an easy formula and a tape measure.

How Do You Measure a Deadbolt? 

When you buy a deadbolt lock set, you'll get a template to assist you in taking the necessary dimensions. The cross bores, the latch bores, the backset, the door thickness, and the lock spacing are all included in the door measures.

You have the option of consulting the instructions in the lockset. The following is a list of the standard dimensions required when installing a deadbolt in your door:

  • Cross bore: A diameter of 1 1/2 to 2 1/8 inches
  • Latch bore: 1 inch in terms of its diameter
  • Door thickness: The thickness is between 1 3/8 and 1 3/4 inches.
  • Door jamb hole: minimum diameter and depth of 7/8 inch and 1 inch, respectively
  • Deadbolt faceplate width: a minimum of 1 inch
  • Deadbolt faceplate height: 2 1/4 inches
  • Backset distance: The distance from the edge of the door to the center of the cross bore is between 2 3/8 and 2 3/4 inches.

Are Deadbolts All The Same Size? 

No, they aren't. Deadbolts aren’t all made equal. They vary in thickness, and thicker is usually better (though not always). They also vary in length — some are longer than others, and some can extend deeper into existing door frames.

What Are The Types of Deadbolts? 

Deadbolt locks are available in three varieties for your home's external doors:


The most basic design for a deadbolt lock consists of a single-cylinder that may be unlocked with a key from the exterior of the building. A thumb turn on the inside door allows for locking and unlocking the door.


You need to use a key from either side of the door to lock or unlock a deadbolt with a double cylinder. This particular style of deadbolt is highly recommended for use on locks close to a window, such as on a front door framed by sidelights on each side. 

Having said that, a double cylinder deadbolt lock should only be installed when it is essential. In the case of a fire or some other emergency, the inhabitants of a residence must evacuate the building as fast as possible. A deadbolt of this sort might be hazardous since it must be unlocked from the inside using a key.


The single-cylinder and double-cylinder deadbolts are more prevalent than this type of deadbolt, which works in a manner that is functionally equivalent to theirs. The mechanism of a vertical deadbolt is located on the internal surface of the door, and the locking bolts function vertically rather than horizontally. 

This type of deadbolt is also known as a vertical lock. Vertical deadbolts have a greater capacity to withstand prying pressures than standard deadbolts, but since they mount on the door's surface, they take up more space than standard deadbolts.

Is The Deadbolt Hole The Same Size as a Doorknob Hole?

No, it is a little bigger. The standard diameter for the hole needed for a doorknob is two inches. The diameter of the hole required for a deadbolt is typically close to two and a half inches. 

How Do I Know What Size Door Lock I Need?

Dead bolt used by a locksmith

If you're changing the locks and latches on your current doors, you may wish to replace them with the same size so that you don't have to do any additional work.

Locks and latches for new or replacement doors can be installed in various sizes, depending on the door's dimensions and equipment.

For doors with paneling or deep frame stops, you will need a lock or latch with the proper backset to fit the desired location for your door, so make sure you measure carefully before purchasing. Take the dimensions of the lock by measuring the distance from the door's edge to the center of the doorknob.

As a result, you'll know the backset size of your lock or latch. The backset is the distance between the forend plate and the keyhole or follower's center.

Can a Deadbolt be Installed on Any Door? 

It is necessary to fit outside doors with deadbolts. To keep your garage and patios safe, you should install deadbolts on any doors that lead to those areas. You can make deadbolts work for any door, even if the door has a variable thickness. It is possible to install the deadbolts on your own, except for doors made of steel.

If your doors have windows, you will run into some problems. If the thumb turn on the lock is less than forty inches from the glass window on the door, an intruder may be able to quickly unlock the door.

If you do not want to put your house or place of business in danger of trespassing or theft, install doors that do not have any windows. You may still have windows in your doors by installing window bars or grates near the door if that is what you choose.

Check your state's laws to ensure that installing window bars is legal before you begin. The installation of window bars presents a potential risk in a fire emergency.

Does a One-sided Deadbolt Provide Adequate Protection?

A deadbolt style lock with a gold key against a white background.

Generally speaking, single-cylinder or one-sided deadbolts are no less secure than double-cylinder ones, although certain exceptions exist.

Because of this vulnerability, an intruder may bypass a single-cylinder lock by shattering a window and reaching through the shattered pane of glass. You should put a double-sided lock on doors with windows nearby to keep your home safe.

Final Thoughts

All outside doors in your home should be secured with deadbolt locks; otherwise, they might not be  secure enough. Adding deadbolts to your doors increases their overall security. The lock should be the proper size to fit your door. Most locksets include a template to help you drill the holes precisely where they should be.

For more articles on deadbolts, check out these related posts: 

How High Should a Deadbolt be on a Door? 

Can You Put a Keypad on a Sliding Door? 

Share this article

Leave a Reply

Your email address will not be published. Required fields are marked *