Are All Interior Door Handles the Same Size? | A Comparative Study


Bari Polished Chrome Knurled Lever on Rose 

Bari Polished Chrome Knurled Lever on Rose 


It’s a common misconception that all interior door handles are the same size. The reality is that they are not. While most people have the same-sized door handles, numerous standards exist, meaning it’s vital to choose the right one for your home. 

The purpose of this post is to offer a comparative study of various internal door standards, including which you should choose and the situations when you might use them. 

Variations in Door Handle Sizes

Door handle sizes vary significantly across several dimensions. These include: 

  • PV or centre-to-centre (CTC): 47.5m, 48.5mm, 70mm or 92mm
  • Backset: 44mm, 57mm, 82mm, 107mm
  • Projection: 38 to 63mm
  • Width: 44mm (standard)

CTC choice relates to door usage. Handles with short CTCs are usually suitable for the smallest interior doors, such as those adorning closets or pastries, while those with standard distances are more appropriate for regular interior doors. Longer lengths may be suitable for doors with more interior traffic. 

Projection affects a door’s usability. Longer projections can make it more straightforward to open heavier doors or those in higher-traffic areas. You typically see short projections on in-built furniture or closets. Longer projections are more suitable for individuals requiring more accessibility. 

The backset determines the compatibility of handles and interior doors. It matters because it determines whether the locking mechanism can extend into the door’s frame. This consideration is essential for interior doors, regardless of purpose. 

Finally, the door thickness matters because it determines the spindle length you require. Most interior doors are 44mm, but you may have something wider if you have insulated or security doors. 

Factors Influencing Size Differences

Various factors influence door handle size differences. Understanding them can help you make sense of why you are fitting one handle type instead of another. 

Door Type

Door type has a significant impact on the handles you install. Interior doors have thinner panels, so they usually have shorter CTCs. By contrast, exterior doors with more elaborate locking mechanisms might have longer CTCs. Double doors can also affect sizing, often requiring larger backsets and locking mechanisms compared to single doors. 


Opening requirements also play a role in handle size and shape. Lever-style handles often require longer CTC distances because of the shearing action they introduce to the door body. Knob-style handles don’t introduce these extraneous forces as such, reducing the CTC. 

Projection also affects the handles’ footprint on the door. Handles that stick out more can increase moment forces on the mount, requiring a thicker, longer and sturdier design. 

Generally, heavier doors require more robust handles. Closets might only need a small one-inch knob, while doors to the living room might require something much larger. 

Manufacturer Specifications

Finally, manufacturers sometimes produce door handles with slight sizing variations due to aesthetic needs, production tolerances or material choices. If choosing a non-standard design, check the product specifications. 

Importance of Size in Handle Selection

Choosing the correct handle size for interior doors is essential for two main reasons: functionality and aesthetics. Getting it wrong may mean the door doesn’t function properly or looks imbalanced. 

On the functional side, consider whether the product offers sufficient grip for efficient operation. Handles with bigger diameters offer superior grasp and may help people with large hands or upper body weakness.

Also, consider the handle’s style if you have any accessibility requirements. Longer projections and lever handles are superior for anyone living with a disability by increasing leverage. 

Lastly, choose a handle compatible with your door thickness. Those that are too wide or narrow will not fit. 

On the aesthetics side, consider handles that complement your doors’ appearance and your room’s theme. Those that are too large can disrupt the local balance, while those that are too small may appear out of place. Traditional doors pair well with ornate and antique handles, while contemporary themes work better with sleek, minimalist handles. Door handles should be pleasing to the eye and reflect your tastes. It has to be something you feel is appropriate for your home. 

Tips For Selecting The Right Handle Size

When selecting a new handle for your door, do the following: 

  • Consider whether the handle is suitable for the amount of usage it will get.
  • Measure all the crucial differences, such as the door width and backset.
  • Check the handle meets your accessibility requirements.                                                                                                                   


Here are some examples that demonstrate why choosing the right handle size is essential. 

Example 1: Grip for Accessibility

People with arthritis or limited dexterity may want handles to offer superior grip and longer levers to help with accessibility. These can help with minimising the force required to open doors. 

Example 2: Homeowner Wanting Superior Aesthetics On A Classical Property

A homeowner who just completed a renovation on a classical property might want door handles with a traditional aesthetic. Getting the choice right could improve balance and proportion in the rooms. 


Not all interior door handle designs are the same size. Therefore, choose products carefully. Getting it wrong could disrupt visual harmony in your rooms, make it harder to open doors or force you to send handles back because they don’t fit. 

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