Skip to content

How to Measure the Size of a Door Lock

This article is a collaborative effort, crafted and edited by a team of dedicated professionals.

Contributors: Muhammad Baballe Ahmad, Mehmet Cavas, Sudhir Chitnis, and Zhen-ya Liu.

✓ Verified & Tested Information

How to Measure the Size of a Door Lock-Most people don’t know how to measure the size of a door lock. Here are some tips on how to do it.

Measuring the Length

Measuring the length of a door lock is one of the most important steps in determining the size and type of door lock to purchase. This is particularly important if you are replacing an existing lock and need to ensure the new one will fit the hole. Fortunately, measuring the length of a door lock is quite straightforward, and it just takes a few simple steps. In this article, we will discuss the best way to measure the length of a door lock.

Measure from the center of the lock to the edge of the door

The door lock size is determined by measuring the distance from the center of the hole in the door to the edge of the door on both sides. This measurement should be taken directly in line with the keyhole, and should not include any margins beyond that point. When measuring, you may need to use a ruler or a straightedge to ensure accuracy. Be sure to not measure too tightly, or it could impact the performance of your lock.

When measuring perfectly centered locks, such as deadbolts, take into consideration any variations in thickness around your doors opening and check against any information guidelines supplied by your manufacturer. It is also important to measure both sides of a double-sided lock as they may vary slightly in size due to aesthetics or security reasons. These measurements are used for most roller style locks and rim locks.

Measurement will also include any liners or faceplates associated with your lock that fit within your door’s opening frame when closed. Measure these separately from inside to outside and make sure that these liners are not forced away from its rightful place when installing new components onto them – this will affect its performance considerably if incorrectly installed. Once you’ve got all of these measurements taken properly you can use them for ordering replacement sizes for your front entry door lock repair project!

Measure the length of the lock from the edge of the door to the center of the lock

To accurately measure the size of a door lock, you will need to know the distance between the edge of the door and the center of the lock. To do this, measure from one end of the door, horizontally across to the center of the keyhole. Make sure that you’re taking your measurements from one corner to another, and not from any other points on your door. If you’re measuring a lever-style handle, make sure that you’re measuring from one side of it instead of measuring from its exact center point. Once you have this measurement down, use it as your baseline for finding a replacement lock for your doors.

Measuring the Width

Before you can purchase the right size door lock, you need to measure the width of the door and the jamb. This is especially important if you are installing a new door lock or replacing an old one. Measuring the width of the door and the jamb accurately will help you find the right size door lock to fit your door. In this article, we will discuss the steps you need to take to measure the size of a door lock correctly.

Measure from the center of the lock to the edge of the door

The most important step in measuring a door lock is determining the precise location of the center. Using a tape measure, measure from the back of the bevel to the center of the deadbolt crossbar. Be sure to keep your tape measure level for an accurate measurement. Once you have determined the center, you can begin to measure from there.

To accurately measure from the center of the lock to the edge of your door, place your tape measure on top of your door and extend it along its length until it meets with one end of your deadbolt lock cylinder’s bevel. Measure this distance and compare it to other manufacturers before buying a new door lock so you can be sure that you are buying one that fits properly. Take special care if you are replacing an existing lock; if it doesn’t fit in either direction (too long or too short) then you may need to modify the edge thickness of your door frame slightly in order to accommodate a new lock.

Measure the width of the lock from the edge of the door to the center of the lock

Accurately measuring the width of a door lock is essential when replacing an existing lock or buying a new one. To measure the width of the lock, start by placing one side of a ruler or a measuring tape against the edge of the door and extend it to the center of the hole in the middle or side. For holes on the left or right side, use a ruler to measure between them. Alternatively, you can also measure portions at a time. Start by marking where each end begins and then add up all smaller measurements to get an accurate total measurement of your door lock’s width. Be sure to use tools that accurately reflect inches and tenths of an inch (or millimeters in some cases) for precision.

Measuring the Depth

When measuring the size of a door lock, it is important to pay attention to the depth. The depth is the distance from the front edge of the lock to the depths of the internal components. Knowing how to accurately measure the depth of the lock is essential to identifying and purchasing the right size lock. Here, we will go over the different methods of measuring the depth of a door lock.

Measure the depth of the lock from the edge of the door to the center of the lock

The depth of the lock is the distance between the edge of the door and the center of the lock cylinder. This measurement is important to ensure that you can install a mortise lock in your door. To measure, start at the edge of the door and use a ruler or measuring tape to measure from where the hole for either side of your mortise lock will be cut into to its center. Once you have your measurement, write it down so you can use it when selecting a mortise lock for your door. When selecting a mortise lock for installation, choose one that has a faceplate no larger than your framing thickness and make sure that its backset (distance from cylinder center to edge) matches your measured depth. Additionally, take care to ensure that other parts such as Latches meet ANSI requirements. With these measurements in hand, you’ll be ready to install new or replacement locks quickly and easily.

Measure the depth of the lock from the center of the lock to the edge of the door

The measurement of the depth of the lock from the center of the lock to the edge of the door is necessary to determine what size drill bit you will need for installation. This particular number is typically written on a label associated with your door. Generally, this measurement should be anywhere from 3/4″ to 1-1/2″ in depth.

To measure the depth accurately, you will need either a ruler or a measuring tape. If using a ruler, be sure that it has both 1/16″ and millimeter increments marked on it. Begin measuring at the edges of where your new lock will be installed, extending out into the center until you arrive at one half of its diameter. Once you have done this, use either your ruler or measuring tape to measure across each side to determine if it can fit with what is presently installed on your door.

When completed, record its measurement and use it as reference against any other measurements that may be taken from other door locks in order to determine which one best fits your needs. Properly measuring for installation will make all the difference between an easy or difficult installation process for your new lock and ultimately ensure that it provides you with robust security for years to come.

Additional Considerations

Aside from simply measuring the length and width of a door lock, there are other factors to consider such as whether the lock is for an exterior or interior door, if it is for a doorknob or a deadbolt, and how secure the lock needs to be. All of these details can make a difference in finding the exact size of a door lock. Knowing these additional considerations can help you ensure that you are purchasing the right size lock for your door.

Consider the type of lock you are measuring

When measuring for a door lock, there are several additional considerations to keep in mind. First and foremost, the type of lock you are measuring for will determine the measurements that need to be taken. For instance, the security requirements of a keyed entry knob may be different than those of a latch-set handle.

In door knob applications, measure from one side of the square section in the middle to the other side – this is also known as a “backset.” Common sizes include 2-3/8″ and 2-3/4″ backsets. Additionally, you will want to know what size bore hole is necessary if it is not already pre-drilled – these are usually 1″ or 1 1/8″.

Another type of lock that needs measurements is a cylinder lock – these usually measure 2 3/8″ or 2 3/4″ from the centerline of one edge of an existing cylinder hole to the opposing face or strike plate. Lastly, in lever handle locks there are three measurements that must be obtained: handing (left hand or right hand), width (distance between two latch points) and mounting (distance between holes for mounting screws).

It’s important to have an accurate measurement when ordering specific parts for any kind of door locks; taking all factors into account can ensure a proper installation and make sure your purchase fits snugly into place.

Consider the type of door you are measuring

When measuring for a door lock, it is important to consider the type of door you are working with. Exterior doors are typically 2-3/8 inches and 2-3/4 inches, while interior doors are generally 1-3/8 to 1-3/4 inches thick. Some locks may require specific measurements or a different type of security such as a steel jamb or reinforced door frame to ensure proper installation. Before starting any project, it is recommended that you confirm the measurements needed as well as checking with the door hardware manufacturer if possible before purchasing a new lock system.

It is also important to consider the size of any handle hardware you may be using in conjunction with your new lock system. Many handles come in varying sizes so measuring and comparing those sizes can help ensure that your desired handle fits properly with your chosen door lock. Additionally, if replacing an existing lock system, you may need to match existing hole dimensions from the old hardware when installing new lockset components. Not all systems will match perfectly, so be sure to double check measurements against the manufacturer’s specs before cutting or drilling into your existing masonry work or other material when replacing an old system with a newer one.

Consider the size of the door jamb

When measuring for a replacement door lock, it is important to consider not only the size of the lock but also the size of the door jamb. The door lock needs to fit into the space that has been cut out for it in the jamb. Precise measurements of both will help to ensure an appropriate fit and easy installation.

Before taking any measurements, inspect the existing jamb for any irregularities or damage. If there are minor problems like splintering or warped wood, they can easily be repaired with some sandpaper and a screwdriver. It’s also important to take note of any hardware already present on the jamb that might interfere with or prevent installation of a new lock, such as hinges, trim pieces, weather stripping or alarm components.

Once all hardware is identified and accounted for, use a tape measure to determine the exact size of both the door lock and jamb space that will need to be filled by it. Measure height first-start at floor level, then measure up along each vertical side until you reach a point two inches above expected finish level (to allow for standard interior door molding). Then measure across each side from top to bottom-start at top edge level and run straight down; for irregularly shaped jambs (because of design features), use this method and note down widths at each section gradually working from left to right until endpoints are reached on both sides (include existing hardware in measurements). Record all figures as this information will come in handy when purchasing your new door lock.

Consider the thickness of the door

When purchasing a door lockset, it is important to ensure the locking mechanism will fit correctly. The two primary measurements you need to determine are the backset and the cross bore. When measuring for the size of lock needed, it is important to also consider additional factors such as the thickness of the door and the type of latch used.

The thickness of a door can range from 1-3/8 inches up to 2-1/4 inches for commercial applications. Most residential door locksets will accommodate for a variety of finishes, including wood, aluminum and steel doors with thickness between 1-3/4 and 2-1/4 inches. Generally speaking, if your door is thicker than 2 inches you may need to purchase an extended strike plate in order to make sure the deadbolt engages fully.

In addition, it’s imperative that you measure properly both horizontally (edge bore) and vertically (cross bore). Edge bores should be located between 2-3/8″ and 2-3/4″, while cross bores should be found between 5/8″ and 1″. Make sure that your lock’s dimensions match those of your specific installation requirements; otherwise you may find yourself replacing your newly bought device in short time. When selecting a lockset be sure to consult with your local home supply or hardware store for their measurement guidelines – even slight discrepancies can cause problems down the line.

How to Measure the Size of a Door LockCheckout this video:

Share this Article