The most common question we are asked by those new to DIY is what size door latch do I need? If you require new latches for your doors but don’t know which size to buy, fear not! Our handy guide below will help you to determine which size of latch to install on your doors!

Latch Size

The two most common sizes of door latch are as follows: 1). 76mm latch with 57mm backset (3 Inch latch with 2 ¼ Inch backset) or 2). 63mm latch with 45mm backset (2 ½ Inch latch with 1 ¾ Inch backset) and the most important measurement to consider is the backset measurement!

If you are replacing the latch on an existing door, you will first need to know what size ‘backset’ you require. The ‘backset’ is the measurement from the centre of the spindle hole to the edge of the door and it is important that the ‘backset’ measurement on your latch matches with that on your door, so you can pass the spindle through the hole, in order to fit your door handles.

Replace Old Latches

The second thing to consider when replacing the latch on an existing door is the size of both the faceplate and strikeplate on your new latch, as you may wish to ensure that it will cover the grooves which were originally cut into the door to accommodate the latch you are replacing.

If you are fitting latches on a new door which has not yet had the spindle hole drilled, we would recommend that you select the 76mm sized latch (with 57mm backset), as this will position your handle pair further into the door and in most instances will also line-up most centrally on the lock stile (edge panel) on your door. You could of course choose either size however, so if you are in any doubt about which size to order you could measure both 57mm and 45mm from the edge of the door to see where you would prefer your handles to be placed!

Read How to Fix Old Door Handles for more helpful tips to guide you through your home improvements.