In ‘Black Powder’ you give the order for the unit before rolling the command dice. The dice may give you 1, 2 or 3 moves. If you don’t have enough moves to complete your order you must try to complete it, even if you don’t like where it leaves the unit. Giving an order is easy if there is a terrain feature – “The brigade will advance onto the hill and take a defensive position.” but not so easy to define if moving across open ground, and you don’t want them to go all the way across.
My regular opponent and I have taken to referring to ‘paces’ where 1 unit of movement (UM for ease hereafter) is 10 paces (We use centimeters instead of inches, but the principle is the same). Thus an order of “The battalion will move 150 paces forward” is a move of 15.
Given I reckon 1 UM is approx 10 yards this works well; strictly a pace is two and a half feet, so 1 UM is 12 paces, but it’s close enough. A scale of 1 UM to 10 yards makes for easy conversion, but there is no reason why you couldn’t call it 8 yards.