Calculate asphalt tonnes from square metres area, thickness, and density. Full metric output for international pavement projects.
Enter area in square metres (m²) or length × width in metres. Thickness in millimetres. Ideal for metric projects across Australia, Europe, NZ and Africa.
Metric calculations align with SI units used in most countries outside the US. Outputs in tonnes (metric tons) and cubic metres.
Results shown in metric tonnes (t). Standard HMA: ~2300 kg/m³. 1 tonne = 1000 kg. Add 5–10% for compaction and wastage allowance.
Enter dimensions to calculate
At standard density 2300 kg/m³. Add 5–10% for compaction and material wastage.
| Thickness | Tonnes / 100 m² | Volume / 100 m² | Typical Application |
|---|---|---|---|
| 30 mm | 6.9 t | 3.0 m³ | Thin overlay / micro-surfacing |
| 40 mm | 9.2 t | 4.0 m³ | Light surface course |
| 50 mm | 11.5 t | 5.0 m³ | Standard surface course |
| 60 mm | 13.8 t | 6.0 m³ | Heavy surface / binder course |
| 70 mm | 16.1 t | 7.0 m³ | Binder / base course |
| 100 mm | 23.0 t | 10.0 m³ | Base course / full-depth |
The metric m² formula is straightforward — area times depth times density. No unit conversions needed when all inputs are in SI units.
Multiply length by width in metres. Example: A commercial car park 80 m × 40 m = 3,200 m². For irregular shapes, break the area into rectangles and sum them. For roads, area = length (m) × carriageway width (m).
Convert thickness from mm to metres (÷ 1,000), multiply by area, then multiply by density and divide by 1,000 to convert kg to tonnes. At 50 mm and 2,300 kg/m³: 3,200 × 0.050 × 2,300 ÷ 1,000 = 368 tonnes. Add 7% waste = order 394 tonnes.
Apply the mix binder content percentage to the total weight. At 5.5% binder: 368 × 0.055 = 20.2 t bitumen and 368 × 0.945 = 347.8 t aggregate. For international projects, cross-reference with the Australia or New Zealand Calculator for region-specific mix density defaults.
This calculator outputs metric tonnes (t), where 1 metric tonne = 1,000 kg. This is not the same as a US short ton (2,000 lb = 907 kg) or a UK long ton (2,240 lb = 1,016 kg). Most international projects (Australia, Europe, Asia, Africa, New Zealand, Canada) use metric tonnes. For US-based projects in square feet and short tons, use the Square Feet Calculator instead.
From quantity surveying on international infrastructure projects to driveway contractors ordering asphalt, the m² input format is the universal standard outside the US.
QS professionals and civil engineers preparing Bills of Quantities for international road, airport, and carpark projects use m² as the standard area measurement. This calculator converts area and thickness directly to metric tonnes for BOQ line items, tender estimates, and variation claims — with bitumen and aggregate broken out separately for material cost scheduling.
Related: Asphalt Cost Calculator
Paving supervisors on site measure completed areas in m² for production tracking and material reconciliation. By comparing actual tonnes placed (from delivery dockets) against the calculated theoretical tonnes for the measured area, supervisors can detect density issues, over-ordering, or material losses before they become costly problems on large contracts.
Related: Asphalt Tonnage Calculator
Paving contractors in Australia, New Zealand, the UK, and Europe quote projects in m² and order asphalt in tonnes. This calculator bridges the two — enter the quoted area and thickness, get the tonnes to order from the plant. Accurate ordering avoids costly truck returns for under-orders or material wastage from significant over-ordering.
Related: Full Metric Calculator
More tools for metric pavement estimation.
Multiply the length and width of your paving area in metres to get square metres (m²). For car parks and driveways, walk the perimeter with a measuring tape or use satellite mapping tools. A standard single-car driveway is around 20–30 m².
Input your required compacted layer depth in millimetres. Light-duty residential work typically uses 40–50 mm; heavily trafficked areas need 75–100 mm or more. The default density of 2.3 t/m³ applies to most dense-graded AC mixes — adjust for open-graded or SMA mixes if needed.
The calculator multiplies area (m²) × thickness (m) × density (t/m³) to produce metric tonnes. Add a 5–10% contingency for trimming and compaction variation before placing your order. Discuss the final volume with your asphalt contractor to confirm mix-specific density values.
At a 50 mm compacted depth and a density of 2.3 t/m³, one tonne covers approximately 8.7 m². At 40 mm depth the same tonne covers around 10.9 m². Coverage drops as thickness increases, so always recalculate when changing the layer depth specification.
In Australia, Austroads AC 14 and AC 10 mixes typically have a compacted density of 2.30–2.40 t/m³. UK DBM and HRA mixes run 2.25–2.35 t/m³. The safest approach is to request the job mix formula (JMF) from your supplier, which will state the design bulk specific gravity, then convert it to t/m³ by multiplying by 1.0 (they are numerically equivalent for water density of 1 t/m³).
No — chip seal (bitumen sprayed seal) does not have a significant layer thickness in the same sense as asphalt concrete. Sprayed seals are quantified by litres of bitumen per m² and stone coverage rate. Use our application rate calculator for sprayed seal projects. This square metres calculator is designed for asphalt concrete (AC) or asphaltic concrete overlays.
Yes. Divide the total tonnes result by the payload capacity of the trucks being used. Articulated tipper trucks typically carry 20–25 t per load; smaller rigid tippers carry 8–12 t. Always confirm payload with the transport contractor, as axle load limits vary by road class and may restrict maximum truck weights in some areas.
Some specifications express asphalt application rates in kg/m² (kilograms per square metre). To convert to total tonnes: multiply kg/m² by your total area in m², then divide by 1,000. Example: A spec calls for 115 kg/m² for a 50 mm dense-graded AC layer (at 2,300 kg/m³). For a 500 m² car park: 115 × 500 ÷ 1,000 = 57.5 tonnes. The kg/m² rate is simply density × thickness in metres: 2,300 × 0.050 = 115 kg/m². You can verify your calculator result by checking the implied kg/m² = total tonnes × 1,000 ÷ area.
This is an important distinction when ordering across borders. A metric tonne (t) = 1,000 kg = 2,204.6 lb, and is the standard in Australia, NZ, the UK, Europe, Canada, and most of the world. A US short ton = 2,000 lb = 907.2 kg — about 10% lighter. A UK long ton = 2,240 lb = 1,016 kg. When using this metric calculator: 10 metric tonnes ≈ 11.02 US short tons ≈ 9.84 UK long tons. Always clarify which "ton" an asphalt plant quote uses to avoid a 10% ordering error. Australian and NZ plants quote in metric tonnes; US plants typically quote in short tons.
For irregular shapes, break the area into simple rectangles or triangles and calculate each section separately. Example: An L-shaped driveway: Section A (10 m × 4 m = 40 m²) + Section B (6 m × 3 m = 18 m²) = 58 m² total. Enter this total area as length × width (e.g., 58 × 1) in the calculator. For curved areas, the formula for a circle is π × r² (about 3.14159 × radius²). For a semi-circular turning area with 4 m radius: 0.5 × 3.14159 × 16 = 25.1 m². Add all sections together for the total m² input. You can also use the Circular Asphalt Calculator for round areas.