At 145 lb/ft³, every cubic foot of asphalt is 0.0725 tons.
Tonnage is the number the asphalt plant actually bills, so this view puts tons front and center. Quote your compacted thickness — hot mix loses about a quarter of its loose depth under the roller.
Why order extra? The headline number is the exact material your project needs. When you actually order, add about 5–10% on top — the “with 5% waste” figure in the result is a safe starting point. That margin covers what you lose to compaction, cuts around edges and corners, and ordinary spillage during handling. It is cheaper to have a little left over than to stop mid-job and wait on a second delivery.