The correct way to determine the answer is to find out what the design weight of the hot mix asphalt (HMA), then compute the number of cubic feet required and multiply the total cubic feet times the weight per cubic foot. Then, divide by 2000 to get the total tons. 148 lbs. Per cf is the approx weight of HMA (we used in State Highway construction) but the weight can vary with different mix designs in different areas.

Now, to try and answer your question. An old rule of thumb for asphalt estimating is based on the assumption that one ton of HMA, covering one square yard, makes a 18 inch deep block of HMA. The rule then requires that you divide the 18 inches by the depth you will be placing it (3 inches in your case). The result is the number of sq yards that one ton will cover at 3 inches deep; or 18 div by 3 equals 6 sq yds per ton at 3 inches. Multiply 6 sy times 9 (9sq ft per sy) = 54 sq. Ft. For 1T at 3".

Checking the two methods: 54 sq ft times 0.25 (3" in feet)= 13.5 cu ft times 148 lbs per cf= 1,998 lbs. As stated above, these calculations are based on an assumes weight of a 148 lbs./cf. Mix.

Now, to try and answer your question. An old rule of thumb for asphalt estimating is based on the assumption that one ton of HMA, covering one square yard, makes a 18 inch deep block of HMA. The rule then requires that you divide the 18 inches by the depth you will be placing it (3 inches in your case). The result is the number of sq yards that one ton will cover at 3 inches deep; or 18 div by 3 equals 6 sq yds per ton at 3 inches. Multiply 6 sy times 9 (9sq ft per sy) = 54 sq. Ft. For 1T at 3".

Checking the two methods: 54 sq ft times 0.25 (3" in feet)= 13.5 cu ft times 148 lbs per cf= 1,998 lbs. As stated above, these calculations are based on an assumes weight of a 148 lbs./cf. Mix.