Although they can come in different sizes the two most common sizes in the uk for internal door latches are 63mm and 76mm.
Measurements for door locks.
Your cylinder locks should be as flush as possible with the handles maximum projection is 5mm if you current lock sticks out by more than 5mm either side of the hanldes then choose a smaller size.
As for how to measure a door frame.
Many older doors had bores that were been smaller.
In the united states there are two common backsets for residential door locks.
Opening heights 3 0 through 4 11 15 16 centered in door height not frame.
Use the smallest figure as your measurement.
All standard bored locks ansi 115 2 161 61l type for mortise lock ansi 115 1 86 type all locations must be altered 3 8 lower and standard strike asa type.
In most cases the door set which is inside of the door and controls the door latch.
Pack your locks with a 2 3 8 inch or 2 3 4 inch latch depending on which backset you specify.
Stand inside the open door facing the jamb.
Dummy sets have no latch and are surface mounted so you can install a dummy set wherever you choose on the door.
This helps to ensure that your door will fit.
Take care to measure carefully as matching the size can be especially problematic in older homes.
Before you learn how to change door locks measure the space where you ll install the replacement.
The distance between the edge of the door and the center of the lock hole.
Cylinder door locks are not difficult to replace if you have basic diy skills you only need two measurements.
Usually the backset measures 2 3 8 inches or 2 3 4 inches.
Measure from the floor to the underside of the trim at the top of the door.
Shop door knobs handlesets.
If one wants to replace their locks on doors that have smaller diameter holes there are 2 options.
1 measure from the center of the door knob hole to the edge of the doorway to find the size of the door set.
Lock bore the diameter of the hole for the lock body.
These sizes are the overall length of the latch or the case.
If you must it is always better to round down than round up.
Measure the width of the door in 3 locations.
Before purchasing a lock measure your door s backset cross bore and thickness to ensure you find the right fit.
You ll want to measure sliding doors from outside of your home looking at the exterior of the door.
Most of the current locks require the standard 2 1 8 bore.
The standard bore is 2 1 8.
2 3 8 inches and 2 3 4 inches.
Measure the height of the door right in the middle.
Measure from the inside edge of the trim on one side to the inside edge of the trim on the other side to get your jamb width if there s trim installed or simply measure the jamb if it s unadorned.