How to set focus to infinty on Nikon AF-S DX 18-105mm f/3.5-5.6G ED VR lens?

How to manually set focus to infinity on Nikon lens Nikon AF-S DX 18-105mm f/3.5-5.6G ED VR in MF mode?
Is there some kind of calculation that depend of the focal length. Can be infinity focus be set on any focal length? Aperture setting?
There's no infinity sign on lens.

Thanks.

Added (1). Aspherical "8"-0.48m/1.48ft
Can this help to solve this mystery?

Added (2). There's no marker for focusing, so "8" infinity sign do not exist!

It looks like an 8 lying down.

Switch to manual focus and turn the focus ring as far as it will go. There's no calculation, but zooming may cause the lens to creep, so double check before you shoot.

Fix at sky (infinity sign looks like '8'). Be sure to turn on MF or choose AE/AF lock on camera

There's no formula!
Look through viewfinder
Point lens at distant object (500 meters plus)
Turn focus ring until image is in focus.

That's the only way

NB turning the focus ring as far as it will go will not focus on infinity - AF lenses need to focus beyond infinity to allow "hunting" room to enable them to home in on the focus point.ie they always go beyond the focus a fraction then come back.

You can just set the centre line to the middle of the upside down 8 symbol, but this is not always accurate.

Try focusing on AF at the 105mm setting on the most distant object you can see ( eg at night, the moon ).
After you have done that, set the switch back to MF. That is what I always do.