Deadbolt Sizes: How to Measure (10 Steps)

Deadbolts Sizes

Deadbolt Sizes: When it comes to deadbolts, size matters; for one, you cannot just pick any deadbolt and fix it on your door without knowing the size that will fit the thickness of your door. It could damage your door and cause problems. What are deadbolt sizes: standard and how to measure?

The most common deadbolt sizes are 2 ¾ and 2 ⅜ inches, which correspond to the backset—the distance from the door’s edge to the lock cylinder’s center. These sizes are standard for residential doors, but measuring the backset accurately is crucial to ensure a proper fit. 

When you understand deadbolt sizes and select the appropriate size for your specific requirements, you can enhance the security of your home and enjoy peace of mind. So in this article, we’ve got you covered on all you need to know about deadbolt sizes. 


How Long Is Deadbolt?

The length of a deadbolt may depend on the specific model and design. But, deadbolts are usually measured from the edge of the door to the center of the cylinder, where the key is inserted. Standard deadbolts generally have a length of 2.375 inches or 2.75 inches for residential applications. 

These deadbolt sizes are the most common and are considered the standard backset measurements in the door industry. The backset refers to the distance from the edge of the door to the center of the deadbolt’s faceplate or strike plate.

On the other hand, commercial deadbolts can have longer lengths to accommodate thicker doors commonly found in commercial buildings. Depending on the door’s thickness and requirements, these deadbolts may have a height of 3 inches or even longer.

However, the length of the deadbolt alone does not determine the security of a door. Other factors, such as the quality of the lock, strike plate, door material, and installation, also play significant roles in determining the effectiveness of a deadbolt.

What Is The Standard Size Of A Deadbolt?

The standard size for a deadbolt is usually around 2 ¾ inches or 2 ⅜ inches. These measurements refer to the backset, which is the distance between the edge of the door and the center of the deadbolt’s keyhole or latch hole. Measuring the backset is important because it ensures that the deadbolt properly aligns with the strike plate on the door frame.

Image "Standard-deadbolt-hole-sizes."
Image of “standard Deadbolt Sizes

As for the diameter of the deadbolt, it is usually around 1 inch. This size allows for a secure fit in the door and provides sufficient strength to withstand excessive force or attempts at tampering. The deadbolt’s bolt, which extends into the strike plate when locked, should be around 1 inch or slightly longer.

Additionally, the faceplate of a deadbolt, which is the metal plate visible on the edge of the door, usually has a standard size of 1 inch by 2 ¼ inches. This size ensures compatibility with most door designs and allows for easy installation.

While these dimensions are standard, variations may be based on specific lock brands or models. Therefore, it is advisable to consult the manufacturer’s specifications or seek professional guidance when choosing and installing a deadbolt.

What Size Is A Deadbolt Cylinder?

The cylinder of a deadbolt refers to the cylindrical housing that contains the locking mechanism. The most common size for a deadbolt cylinder is usually around 1 inch in diameter. This standard size allows the cylinder to fit into the pre-drilled hole in the door, accommodating most residential and commercial door thicknesses.

The cylinder length can vary based on the door thickness and the particular deadbolt model. The cylinder length is commonly around 2.5 inches to 3 inches for residential doors. This length is sufficient to penetrate the door and securely engage with the locking mechanism.

Deadbolt cylinders can sometimes be found in different lengths or adjustable to accommodate different door thicknesses. Adjustable cylinders are especially useful for doors with non-standard dimensions or for retrofitting deadbolts onto existing doors without extensive modifications.

How Do You Measure A Deadbolt Size?

To measure the size of a deadbolt, you will need to determine two key measurements: the backset and the cross bore.

The backset refers to the distance between the edge of the door and the center of the hole where the deadbolt is installed. The standard backset size for most residential doors is 2-3/8 inches or 2-3/4 inches. To measure the backset:

  • Close the door and locate the edge where the deadbolt will be installed.
  • Measure the distance from the edge of the door to the center of the existing hole. Use a tape measure or ruler to get an accurate measurement.
  • Common backset sizes are 2-3/8 inches (60mm) and 2-3/4 inches (70mm). Confirm which size matches your measurement.

The Crossbore is the diameter of the hole drilled through the door for the deadbolt mechanism to fit. Most deadbolts have a standard cross-bore size of 1 inch or 2-1/8 inches. To measure the cross bore:

  • Measure the diameter of the existing hole in the door using a ruler or calipers. Ensure you measure across the center of the hole to get an accurate diameter.
  • The standard sizes are 1 inch (25mm) and 2-1/8 inches (54mm). Verify which size matches your measurement.

When you first know the standard size for the backset and cross-bore, it will help you to select a deadbolt that fits appropriately in your door.

Watch this! Deadbolt Sizes


Deadbolt Sizes: How To Measure -Step-By-Step Process

Deadbolts come in various sizes, and measuring ii to know the size is very important when replacing or installing a new deadbolt lock on a door. Here is a step-by-step process to measure a deadbolt size:

  1. Gather the necessary tools: To measure a deadbolt, you will need a measuring tape or ruler, a pen or pencil, and a piece of paper.
  2. Locate the deadbolt: the deadbolt is usually positioned above the doorknob, towards the center of the door.
  3. Measure the backset: The backset refers to the distance between the door’s edge and the deadbolt’s center. Measure from the center of the deadbolt to the edge of the door. Common backset measurements are 2-3/8 inches or 2-3/4 inches.
  4. Measure the cross-bore hole: The hole is the larger hole in the door where the deadbolt mechanism is inserted. Measure the diameter of the cross-bore hole using a measuring tape or ruler. Common sizes for cross-bore holes are 2-1/8 inches or 1-1/2 inches.
  5. Measure the edge bore hole: The edge bore hole is a smaller hole on the edge of the door where the latch mechanism is inserted. Measure the diameter of the edge bore hole using a measuring tape or ruler. Common sizes for edge bore holes are 1 inch or 1-1/8 inches.
  6. Measure the diameter of the deadbolt’s faceplate, which is the metal plate visible on the edge of the door. Measure the width of the faceplate from one side to the other.
  7. Measure the deadbolt’s total length from the faceplate’s edge to the end of the bolt itself.
  8. While measuring, pay attention to any additional features of the deadbolt, such as a thumb turn or a keyhole. Measure their dimensions if necessary.
  9. Record the measurements: Write down the measurements you obtained for the backset, diameter, length, and any other relevant features.
  10. Consult the deadbolt sizing chart: Once you have the measurements, refer to a deadbolt sizing chart provided by the manufacturer or a hardware store. Based on the recorded measurements, the chart will help you identify the appropriate deadbolt size.

With accurate measurements in hand, you can confidently choose the right deadbolt that matches the size requirements.

Conclusion Deadbolt Sizes

There you have it! Everything you need to know about deadbolt sizes. To ensure proper installation and security, it is recommended to consult with a professional locksmith or refer to the manufacturer’s specifications when selecting and installing a deadbolt. Properly measuring and fitting the deadbolt to the door is important as it makes the process easy and offers you optimal functionality.


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