To Calculate Armour Stone Retaining Wall Cost Click Here. Jun 07 2021 Armour Stone 12 inch high Characteristics 700 skid is the price On average there are 6 7 pieces of this armor stone in a skid with an average length of about 2 5' Each stone is 12 inches high the length is random The bed depth is from 1 5' to 2' On average one armor stone.