If you're replacing a uPVC or composite door handle, you've probably come across the term "centres." It's one of the most important measurements when choosing replacement handles or matching a new gearbox.

Getting the centres wrong means the handles simply won't fit the locking mechanism.

What Are Handle Centres?

The centre measurement is the distance between:

• The centre of the spindle (the square hole the handle passes through)
• The centre of the keyhole (where the euro cylinder sits)

This measurement is always taken from the centre of one hole to the centre of the other, not from the edges.

It's measured in millimetres (mm).

To learn more about the different measurements used on door handles, read The Complete Guide to uPVC & Composite Door Handles.

The Most Common Handle Centres

The most common handle centres found on uPVC and composite doors are:

• 92mm – by far the most common
• 70mm
• 68mm
• 62mm
• 48mm
• 35mm (found on some older doors)

Older doors sometimes use less common centre measurements, particularly if the locking mechanism is now obsolete.

Why Are Centres Important?

The gearbox is manufactured with a fixed distance between the spindle and the cylinder.

The handles must match this distance exactly.

For example:

• A 92mm gearbox requires 92mm handles.
• A 70mm gearbox requires 70mm handles.

Even a difference of a few millimetres means the fixing holes and keyhole won't line up.

The Gearbox Determines the Centres

Many people think the handles determine the size.

In reality, it's the gearbox that dictates the handle centres.

The handles are simply designed to match the gearbox already fitted inside the door.

That's why, when replacing handles, it's important to identify the correct centre measurement first.

To understand how the locking mechanism and gearbox work together, see The Complete Guide to Multipoint Mechanisms.

Replacing the Gearbox

If you're replacing a failed gearbox with an identical model, the centre measurement usually stays exactly the same.

However, if:

• The original gearbox is obsolete
• A compatible replacement is being fitted
• The locking mechanism is being upgraded

the centre measurement may change.

In these cases, new handles with the correct centres are often required.

Other Measurements That Matter

Centres aren't the only measurement to consider.

Replacement handles also need the correct:

• Screw fixing centres
• Spindle size
• Backplate length
• Handle offset
• PZ measurement (the centre measurement)

All of these must match the door and locking mechanism.

For a guide to the different handle styles available, read A–Z of uPVC & Composite Door Handle Types.

Why Older Doors Can Be More Complicated

Many older doors no longer have replacement parts available from the original manufacturer.

When fitting compatible gearboxes or upgrading obsolete mechanisms, it may also be necessary to replace:

• Door handles
• Keeps
• Lock cylinders

This ensures everything works together correctly.

To understand how all these components fit together, see The Complete Guide to Door Components & Hardware.

Don't Guess the Measurement

Although 92mm centres are extremely common, not every door uses them.

Ordering the wrong handles can result in:

• Fixing holes not lining up
• The keyhole sitting in the wrong position
• The spindle not engaging correctly
• Handles that simply won't fit

Taking accurate measurements before ordering replacement parts saves both time and money.

If you're also replacing the lock cylinder, How to Compare Lock Specifications explains what else to consider before buying.

It's About Compatibility

When replacing a gearbox or door handles, the centre measurement is one of the most important dimensions to get right. The gearbox determines the handle centres, and both parts must match perfectly for the lock to operate correctly. If you're upgrading an obsolete mechanism, changing the handles at the same time is often the best way to ensure everything fits and functions as intended.

For further reading, you may also find these guides useful:

• High Security Door Handles
• A–Z of uPVC & Composite Door Handles
• Door Handle Moves but Won't Open Door
• Why Won't My Door Handle Lift?
• What Makes a Lock Sold Secure Approved?
• Understanding Door Lock Security Standards – TS007, Secured by Design and Insurance Requirements Explained
• The Complete Guide to Home Door Security