Lift Angle

What is Lift Angle of a watch movement?

The number of degrees the balance wheel turns while making contact with the fork of the escapement. The movement’s lift angle is represented in degrees (for example: 52°).

It is necessary to know the lift angle when determining the accuracy and performance of a movement. Combined with the beat rate (BPH, VPH), you can find the balance amplitude on a timegrapher (aka watch timing machine).

While most lift angles are somewhere between 48-54 degrees, you may see some folks use a common lift angle number (52° is a generally assumed average and also the default lift angle on most timing machines) and say that it doesn’t matter or “it’s close enough”. That is not a helpful approach for getting an accurate picture of how well the watch is functioning, and if you’re looking to get more than the rate of timekeeping from your timing machine, then you will want to input the correct lift angle.

How to Determine Lift Angle?

If you’re getting deeper into the watchmaking rabbit hole or starting to do your own watch repairs, you’ll eventually need to find the movement’s lift angle.

Caliber Corner makes an effort to list the known lift angle for each movement, but sometimes it is unconfirmed.

This video that explains what a balance lift angle is and the formula to figure it out.