Usually, 6 feet (about 3 meters). The reason they do that, is because of the tracking when they’re ion battle.

Otherwise, as @neidu3@sh.itjust.works just said, usually arms length.

An arms length. We used to be sorted be height and you put your arm out and shuffle in until just touching with your finger tips. Then arms down and you are at attention and in formation.

Usually at arms length. Put your arms up horizontally with fist closed, and you should barely be able to skim the ones next to you or in front. After a while you know the correct distance we’ll enough that you don’t really need to use arms. Afterwards, the official cert issues “adjust left” (or right), where everyone turns their heads and make sure they’re lined up perfectly.

The only exceptions were some special drill formations ns which was almost shoulder to shoulder.

At ‘half arm intervals’ you raise your right arm, fist clenched and adjust your position until your thumb is on the nex guys spine.

This video is old, but this is how it’s done: Dress Right, Dress