Hello MartinMJD,
The distance from handle centre to door lock centre is approximately 53mm.
The backset will depend on the lock used, as this is the distance from the front of the lock case to the centre of the spindle and just dictates how far the handle will be from the edge of the door.
Thank you for using Screwfix Q&A.
Answered by: JTremain
Date published: 2021-01-21