The calculation converts area and thickness to volume, then multiplies by material density to get weight. A waste factor accounts for over-spray, trimming, and handling losses.
Tom is resurfacing a car park: 40 m long, 20 m wide, with a 50 mm dense-grade wearing course and a 5% waste allowance.
Density values used: Dense-grade 2.40 t/m³, Open-grade 2.20 t/m³, Mastic 2.30 t/m³, SMA 2.35 t/m³, Pure bitumen 1.04 t/m³. These are representative mid-range values. Ask your supplier for the specific density of their mix design.
Bitumen is the black, viscous hydrocarbon binder distilled from the heaviest fractions of crude oil. At room temperature it is semi-solid and tacky; heated above 150°C it becomes fluid enough to coat aggregate and be laid as a pavement surface. Road-paving bitumen is graded by penetration (how far a standard needle enters the material at 25°C), with grades 40/60, 60/70, and 100/120 covering most road and driveway applications.
Asphalt concrete is made by mixing hot bitumen with carefully graded aggregate, then compacting the mixture while hot. The aggregate provides structural strength; the bitumen binds it together and seals out water. Bitumen typically accounts for 4.5 to 6 percent of the total mix weight in a standard dense-grade formulation.
In the UK and Australia, "bitumen" and "asphalt" are often used interchangeably in everyday speech. In technical contexts, bitumen is the binder and asphalt is the composite material. In North America, "asphalt" almost always refers to the finished pavement, while the raw binder is called "bituminous cement" or "asphalt binder."
Installed driveway costs vary significantly by country and site conditions. The figures below cover sub-base preparation, binder course, and wearing course for a standard residential driveway.
| Region | Installed cost | 50 m² driveway |
|---|---|---|
| UK | £40–£80 per m² | £2,000–£4,000 |
| Australia | AUD $50–$110 per m² | AUD $2,500–$5,500 |
| USA | $7–$12 per sq ft | $3,750–$6,450 |
The largest cost variable is sub-base preparation. An overlay on an existing sound surface costs far less than cutting out soft ground and building a new crushed-stone base. Machine-laid paving over large areas reduces cost per m² compared to hand-applied work in tight spaces.
Modified bitumen roofing is a flat-roof membrane made from petroleum-based bitumen reinforced with polymers to improve flexibility and UV resistance. It is a roofing product and is entirely separate from the paving bitumen and asphalt mix this calculator covers.
Two main types exist. APP (atactic polypropylene) sheets are torch-applied with an open flame, creating a fused bond to the roof deck. SBS (styrene-butadiene-styrene) sheets remain flexible at low temperatures and can be cold-applied with adhesive or torched depending on the specification. Both types are reinforced with polyester or fibreglass matting.
Modified bitumen roofing costs $3 to $7 per square foot installed in the US and lasts 20 to 30 years with proper maintenance. If you are searching for a roofing quantity tool, note that the calculator on this page is designed for road and driveway paving applications only.