Use this asphalt calculator to estimate how much asphalt (tarmac) in volume (cu ft, cubic yards or cubic meters) and weight (tons or tonnes) you would need for a driveway, school yard, pavement, road, etc.. The calculator uses conventional hot mix asphalt density.

Calculating how much asphalt you need

Many road builders and just people who want a nice driveway to their home are faced with estimating the amount of Hotmix Asphalt (HMA, also bitumen, blacktop, Tarmac) they need to cover a given area with. Our asphalt calculator (a.k.a. tarmac calculator) is of great utility in such cases, but you should keep in mind that the results will only be as good as the measurements entered into it. Also, the tool employs standard asphalt density of 145 lbs/ft³ (2322 kg/m³) which may be somewhat different in each particular case depending on the precise asphalt mixture purchased. The calculation process is:

1. Estimate the volume of asphalt needed, using geometrical formulas and plans or measurements, including width, length, and depth (thickness).
2. Estimate the density of the hotmix to be used. Standard density for asphalt is 145 lb/ft³ (2322 kg/m³).
3. Multiply the volume by the density (in the same units) to get the weight

Supported measurement units include inches, feet, yards, meters, and centimeters. As measurements are not always precise and waste might result from the application process, it is wise to consider purchasing 5-6% more asphalt than estimated. This should prevent running just short of what is actually needed. If the asphalt calculator outputs you require 10 tons of asphalt, you should instead purchase 10.5 or 11 tons to be on the safe side and avoid unnecessarily high transportation costs.

In case the area you are calculating has an irregular shape, what you want to do is divide it in several regularly-shaped sections, then calculate each of their volume and asphalt requirements using the calculator. Finally, sum them up together. In case you end up needing to do this for a large number of sections, you might use our summation calculator. Reasonable approximations can be made for slightly irregular shapes by taking the average length or width, but in more complex scenarios and the need for an accurate hot mix asphalt estimation you should consult a professional.

Asphalt basics & applications

Asphalt is a black, very sticky, and highly viscous liquid, or sometimes semi-solid, form of petroleum. It can be found in natural deposits, but is more often the result of refinement, and is classed as a pitch. Asphalt is highly recyclable, providing cost savings and environmental benefits.

Asphalt (tarmac) is widely used as a road surface, be it for highways, inner city and inter-city roads, local roads, car parks, for paving driveways and pavements. These are the primary reasons people are using our calculator as well. It is estimated that around 94% of the 2.6 million paved roads in the U.S. are made from it. You can also see it on racetracks, tennis courts, and dams. Its water resistance makes it great for cable and pipe coatings, and waterproofing in general. Asphalt is used for bituminous waterproofing products, where it is a part of roofing felt and is used for sealing flat roofs. Bitumen has other great qualities as well: durability, high traction, low light reflectivity, etc.

When used for road construction it usually serves as a binding agent in the production of asphalt concrete. Bitumen is mixed with fine and coarse aggregates, e.g. sand, gravel, and crushed rock. Recycled polymers (e.g., rubber tyres) may be added to the hot mix asphalt to modify its properties depending on the intended ultimate application.

Asphalt is usually sold by the tonne from companies specializing in construction, usually road construction and roof water-proofing. Our hot mix asphalt calculator will help you estimate how much of it you need, approximately.

Types of asphalt

Contrary to what you may think, there is more than one type of blacktop, mainly depending on the temperature during mixing. Selecting the right type is important, as some asphalts are better suited to particular applications than others.

Type	Description
Hot Mix Asphalt	Also “Dense-Graded Mix”, this is the most widely used type, ideal for all traffic conditions, for surfacing and repairing needs, great friction. During production the binder is heated at high temperatures to reduce viscosity and to remove all moisture prior to mixing. The asphalt density used in this calculator most closely matches this type of material.
Warm Mix Asphalt	Used at roughly a third of road-paving projects, this asphalt is produced at lower temperatures than HMA and is suitable for paving during off-season months or at overnight projects.
Driveway Mix Asphalt	Cheaper mix that is tailored to use in driveways and parking lots. It includes crushed stone, sand and gravel.
Porous Asphalt	It is designed only with crushed stone and a few grains of sand in the mix, making it permeable to water. More expensive, but removes the need for drainage. It requires an open-graded stone bed of such a size and depth, so water does not rise to the asphalt level.

Our asphalt calculator uses an average asphalt density of 2322.7 kg/m³ by default and currently does not offer customization of this computational parameter. You will need another tarmac calculator if the density differs significantly in your case. Most asphalt, hot mix asphalt included, has a lifespan of over 20 years if applied and maintained appropriately, and if it is not subject to significantly higher loads than it was planned for.

Asphalt calculation: ton vs tonne, tons vs tonnes?

When calculating asphalt weight, make sure you do not confuse tonne (metric ton) with ton (short ton). The first is used by all countries in the world, except the U.S. and is defined to be equal to 1000 kg by the international body of standardization. The ton is currently only used in the United States and is equal to 2000 pounds (2000 lbs). The difference between the two is not huge but can quickly add up to a significant number as the amount increases. Selecting the proper unit system in our calculator will help avoid this issue.