Asphalt Tonnage Calculator

About the Asphalt Tonnage Calculator

Calculates the tonnage of asphalt needed to pave an area to a given compacted thickness, using a typical asphalt density.

How to use this calculator

1. Enter the paving area in square meters or square feet, using the unit required by the calculator.
2. Enter the asphalt thickness, usually in meters or feet, matching the area unit.
3. Enter the asphalt density, which is often given in tonnes per cubic meter or a similar unit.
4. Read the estimated tonnage, then round up a little if you need extra for waste or compaction.

The formula explained

The formula \( tonnes = area \\times thickness \\times density \) computes the mass of asphalt needed from the space to be paved. It works because area multiplied by thickness gives volume, and volume multiplied by density gives weight.

• tonnes = the estimated mass of asphalt needed
• area = the size of the paving surface
• thickness = the depth of the asphalt layer
• density = the mass per unit volume of the asphalt

Step by step method

1. Make sure the area and thickness use compatible units, so the volume comes out correctly.
2. Multiply the area by the thickness to find the volume of asphalt needed.
3. Multiply the volume by the density to estimate the total tonnage.

Worked example

Problem. You need to pave an area of \(120\) square meters with an asphalt layer that is \(0.08\) meters thick. The asphalt density is \(2.4\) tonnes per cubic meter. How many tonnes do you need?

1. First find the volume, \(120 \\times 0.08 = 9.6\) cubic meters.
2. Then multiply by density, \(9.6 \\times 2.4 = 23.04\) tonnes.
3. So the estimated asphalt needed is \(23.04\) tonnes.

Tips and common mistakes

• Check units carefully, because mixing square feet with meters will give a wrong result.
• If the job is large or has uneven ground, add a small extra amount for waste, compaction, and shaping.

Frequently asked questions