Ok I have just got a new Silva type 4 compass, the Tritium one for extra glow in the dark. My problem is that the main gradient is in mills and it is hard to compare these mil markings with the degrees marking so I am after a conversion table or a formula. So if anyone could help I would be very grateful.

Thanks in advance Roger.

Rog if you do a search for Mils in the forum you will get some threads on navigation etc

Basically there are 6400mils in 360 degs
approx 18mils/deg

Haven't used mils since army days prefer degs these days easier to use

I use a mils compass and I wouldn't use degrees unless I had to.

The mil scale is based on the metric system and is very easy to use. As the graduations are smaller it is a more precise system than the degree. 1 mil being around an 18th of a degree.
There are 6400mils in a a circle.
1mil= 1 metre at 1Km. Therefore:
If you took a bearing of 1600mils and marched for 1Km, then you remembered you hadn't added GMA (say 90mil,) then you would be 90m out from where you should be.
At 2Km you would be 180m off and so on.

The equivalent common degrees to mils are shown below:
0/ 360-------0/6400
90-----------1600
180----------3200
270----------4800

When converting bearing to backbearings simply add 3200mils if is less than 3200mils, or subtract 3200mils if greater than 3200mils.

i.e bearing of 5600mils becomes 2400mils backbearing.