Lock Shop Direct help and advice
Lock and Door Hardware Measurement Guides
Use our step-by-step guides to identify and measure replacement locks, cylinders, handles and security hardware. Each guide explains the key dimensions and product features to check before you order.
Measure before ordering: Similar-looking products can have different dimensions and fixing positions. Measure in millimetres, compare every relevant feature on the product page and do not rely on appearance alone.
Door locks, cylinders and handing
Cylinder guide
Measure the internal and external sides of euro, oval, thumbturn, single and double cylinders from the centre fixing screw.
View cylinder guide →
Lock guide
Check the backset, case width, case height, forend length and forend width of an existing mortice lock or latch.
View mortice lock guide →
Lock-case guide
Identify the cylinder profile and measure the case, backset, centres, forend and fixing positions of a replacement lock case.
View lock-case guide →
Rim-lock guide
Check the key measurements and features needed when replacing a surface-mounted nightlatch, rim deadlock or rim sashlock.
View nightlatch guide →
Identification guide
Work out whether a door or product is left handed or right handed and whether the door opens inward or outward.
View door handing guide →
uPVC, composite and window hardware
Multipoint-lock guide
Identify the manufacturer, locking operation, backset, PZ centres, faceplate and positions of hooks, rollers or deadbolts.
View multipoint lock guide →
Handle guide
Measure PZ centres, screw centres, backplate dimensions, spindle position and other key handle measurements.
View door handle guide →
Window guide
Measure the espag backset, strip length and faceplate, then check handle screw centres, spindle and step height.
View window hardware guide →
Other locks and security hardware
Cabinet-lock guide
Check barrel length, cam or tailpiece style, head shape, fixing type and keying requirements for lockers, cabinets and drawers.
View cam lock guide →
Padlock guide
Measure body width and thickness, overall height, shackle thickness, clearance width and clearance height.
View padlock guide →
Exit-hardware guide
Understand the difference between panic bars and emergency-exit devices and identify the door and application requirements.
View panic hardware guide →
Door-closer guide
Compare closer types, mounting arrangements and features before choosing an overhead, concealed, slide-arm or floor-mounted closer.
View door closer guide →
Garage-security guide
Identify garage-door measurements, handle and spindle types, and the dimensions needed for roller-shutter locks.
View garage security guide →
Gate-security guide
Compare suitable lock and security options for common timber, metal, side and driveway gate arrangements.
View gate security guide →
Before you start measuring
1
Identify the product
Look for a manufacturer name, product code or stamp. Photograph the complete item and any markings before removing it.
2
Measure in millimetres
Use a steel ruler or tape measure, take each measurement twice and record it clearly. Include the faceplate and fixing positions where shown.
3
Compare every feature
Check dimensions, handing, operation, fixing type, spindle, finish and locking-point layout against the selected product page.
Only remove an existing lock or fitting where it is safe to do so and you are confident you can refit or secure the door, window or cabinet afterwards.
Not sure which replacement you need?
Send our team clear photographs and your measurements before ordering. For the best chance of a quick identification, include:
- A photograph of the complete product in position.
- Front, side and rear views where possible.
- A close-up of all names, stamps and product codes.
- A photograph showing each measurement against a ruler or tape.
- The door, window, cabinet or gate material and thickness.
Planning a master key system?
A master key system is designed around who needs access to each door rather than a single product measurement. See our Master Key Systems page or contact us with your door and access requirements.
These guides are intended to help identify common replacement products. Hardware can vary between manufacturers and product generations, so always compare the complete specification before ordering. Contact us where compatibility is uncertain.