Locker Lock Dimensions and Standards UK: Sizes, Cam Lengths and Retrofit Guide (2026)

Locker lock dimensions matter when replacing, upgrading or specifying locks for lockers. The right lock must match the locker door thickness, fixing hole, cam length, spindle length and lock body depth.

This guide explains standard locker lock dimensions in the UK, how to measure a locker lock correctly and what to check before buying replacement or retrofit locker locks.

Quick answer: Most locker lock sizing checks involve the fixing hole, cam length, spindle length, door thickness, lock body depth and fixing footprint. Always measure the existing lock and locker door before ordering a replacement.

For fit checks before ordering, use our locker lock compatibility guide. If you are still choosing the lock type, use the locker lock selection tool UK. To view product options, see our locker locks.

What are standard locker lock dimensions?

There is no single universal locker lock size. Many lockers use similar cam lock and latch lock formats, but dimensions vary by manufacturer, lock type and locker age.

The most important locker lock dimensions are:

• Fixing hole size
• Cam length
• Spindle length
• Door thickness range
• Lock body depth
• Fixing footprint
• Rotation direction
• Cam offset or crank shape

These measurements decide whether a lock will physically fit, close correctly and hold the locker door securely.

How to measure a locker lock

Remove the existing lock if possible. Then measure the lock and door with a ruler, tape measure or callipers. Use millimetres for accuracy.

• Measure the door thickness: Check the thickness of the locker door panel where the lock passes through.
• Measure the fixing hole: Record the height and width of the cut-out or round hole.
• Measure the cam: Measure from the centre of the lock barrel to the end of the cam.
• Measure the lock body depth: Check how far the lock projects inside the locker.
• Measure the fixing footprint: Check screw holes, fixing nut size or mounting plate position.

Do not rely only on the visible front face of the lock. Two locks can look similar from the outside but use different cams, bodies or fixing systems behind the door.

Cam lengths explained

The cam is the metal arm at the back of the lock. It rotates behind the locker frame to secure the door.

Cam length affects how far the locking arm reaches. If the cam is too short, it may not catch the frame. If it is too long, it may hit the locker body or fail to turn properly.

Common cam checks include:

• Overall cam length
• Distance from lock centre to cam end
• Cam width
• Cam thickness
• Straight, cranked or offset cam shape
• Clockwise or anti-clockwise locking rotation

For replacement projects, keep the old cam if it is still usable. In some cases, the existing cam can help confirm the correct replacement lock setup.

Spindle lengths explained

The spindle connects the lock mechanism to the cam or latch system. Spindle length is important on combination locks, coin locks, digital locks and some retrofit systems.

A spindle that is too short may not engage the lock properly. A spindle that is too long may stop the lock sitting flush against the door.

When checking spindle length, measure the full projection from the rear of the lock body to the cam or latch connection point.

Locker door thickness compatibility

Locker locks are designed to work within a door thickness range. Thin steel locker doors, reinforced doors and timber or laminate doors may need different fixing arrangements.

Always check:

• Door panel thickness
• Whether the door has a folded edge
• Whether the lock sits on a flat surface
• Whether the lock nut or fixing plate has enough thread engagement
• Whether the cam clears the frame after fitting

This is especially important when upgrading from a simple keyed cam lock to a combination, coin-operated or electronic locker lock.

Fixing hole sizes

The fixing hole is the cut-out in the locker door where the lock is mounted. Some locks use round holes. Others use shaped holes, square holes, rectangular holes or fixing plates.

Before ordering, check both the visible hole and any hidden fixing marks behind the lock. Older lockers may have non-standard cut-outs, enlarged holes or previous retrofit changes.

If the fixing hole is too small, the new lock may not fit. If it is too large, the lock may sit loosely or fail to secure properly without an adaptor plate.

Lock body depth

Lock body depth is the distance the lock projects inside the locker door. This matters because the lock must not hit shelves, locker sides, internal hooks or the locker frame.

Electronic and combination locks are often deeper than standard keyed cam locks. Check the internal clearance before upgrading.

Metric vs imperial sizing

Most UK locker lock measurements should be taken in millimetres. Older locks, imported products or legacy specifications may refer to imperial sizes.

Do not round measurements too heavily. A small difference can affect fit, especially with fixing holes, cams and lock bodies.

Imperial size	Approximate metric size	Use with care?
1/2 inch	12.7 mm	Yes
3/4 inch	19.05 mm	Yes
1 inch	25.4 mm	Yes

When possible, confirm the manufacturer’s metric specification rather than converting from old imperial descriptions.

Retrofit sizing checks

Retrofit locker locks need more checks than direct replacements. This is because the new lock may use a different body shape, fixing method or operating mechanism.

Before retrofitting locker locks, check:

• Existing lock type
• Door thickness
• Fixing hole size
• Fixing footprint
• Cam length and cam shape
• Spindle length
• Internal lock body clearance
• Door swing and frame clearance
• User model, such as shared-use or assigned-use lockers

For a full fit assessment, use the locker lock compatibility guide before choosing replacement products.

Common locker lock dimensions to record

Dimension	Why it matters	How to check
Door thickness	Confirms whether the lock can clamp securely	Measure the door panel at the lock position
Fixing hole	Confirms whether the lock body fits the door	Measure height, width or diameter
Cam length	Confirms whether the lock catches the frame	Measure from lock centre to cam end
Spindle length	Confirms correct mechanism engagement	Measure rear projection from the lock body
Lock body depth	Confirms internal clearance	Measure how far the lock projects inside the locker
Fixing footprint	Confirms screw, nut or plate alignment	Compare the old lock with the new lock template

Choosing the right lock after measuring

Once you have the key dimensions, choose the lock type based on how the locker will be used.

• Assigned staff lockers: Keyed locks or mechanical combination locks often work well.
• Shared-use changing rooms: Coin locks, free-use combination locks or digital locks may be better.
• Wet areas: Choose corrosion-resistant locker locks.
• High-traffic areas: Choose robust locks with simple user operation.
• Retrofit upgrades: Check body depth, fixing holes and cam compatibility first.

Use the locker lock selection tool UK to narrow the choice by environment, usage model, security level and budget.

When to replace like-for-like

A like-for-like replacement is usually best when the existing lock type works well and only damaged or missing locks need replacing.

This keeps installation simple. It also reduces the risk of needing new holes, adaptor plates or door modifications.

When to upgrade instead

An upgrade may be better if the current lock system causes lost key problems, poor control, heavy admin or regular user issues.

For example, a site may move from keyed locks to combination locks to reduce key replacement. A leisure centre may choose coin locks or digital locks for shared-use lockers. A workplace may choose electronic locks for flexible staff storage.

Before upgrading, check physical compatibility carefully. Many upgrade problems are caused by lock bodies, cams or fixing holes not matching the existing locker doors.

View locker lock products

Total Locker Service supplies replacement and retrofit locker locks for schools, workplaces, gyms, leisure centres, factories and public facilities.

If you are unsure which lock will fit, measure the existing lock and locker door first. Then compare the dimensions with the replacement lock specification.

FAQ: Locker lock dimensions and standards UK

Are locker lock sizes standard?

Locker lock sizes are not fully standard. Many locks use common formats, but fixing holes, cams, spindles, bodies and door thickness compatibility can vary.

What is the most important locker lock dimension?

The most important dimensions are the fixing hole, door thickness, cam length and lock body depth. These usually decide whether the lock will fit and work correctly.

How do I measure a locker cam lock?

Remove the lock if possible. Measure the fixing hole, door thickness, cam length, cam shape and lock body depth. Also check whether the cam turns clockwise or anti-clockwise.

Can I replace a locker lock with a different type?

Yes, but you must check compatibility first. Combination, coin-operated and electronic locks may need more body depth, different fixing holes or different cams than the original lock.

What happens if the cam length is wrong?

If the cam is too short, the locker may not lock securely. If it is too long, it may hit the frame or stop the lock from turning properly.

Should locker locks be measured in millimetres?

Yes. UK locker lock specifications are best checked in millimetres. This gives better accuracy than approximate imperial conversions.

Do electronic locker locks fit standard locker doors?

Some electronic locker locks are designed for retrofit use, but not all will fit every locker. Check the fixing hole, lock body depth, door thickness and cam position before ordering.

Where should I go next?

Use the locker lock compatibility guide for fit checks, the locker lock selection tool UK for choosing the right lock type, or view our locker locks.