Calculate asphalt tonnage, volume and cost for driveways, parking lots, footpaths and roads — with a correctly calculated weight formula and an honest waste allowance.
Informational only. Loose asphalt is typically spread 20–25% thicker than the finished compacted result before rolling — useful for a paving crew, but it does not change the weight to order, since compacted density already gives the correct mass for your compacted thickness.
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| Item | Value |
|---|
Crushed rock and gravel are essential materials in Australian construction and landscaping. They are sold by weight (tonne) or volume (m³) depending on the supplier.
| Application | Material | Depth |
|---|---|---|
| Residential driveway | Dense grade | 25–40 mm |
| Car park | Hot mix | 40–50 mm |
| Footpath / path | Fine asphalt | 25–30 mm |
| Road base course | Hot mix | 50–75 mm |
| Overlay / resurface | Dense grade | 25–30 mm |
Written and reviewed by Mohsin Iqbal · Last reviewed August 2026
Asphalt (also called blacktop or bitumen paving) is a mix of crushed stone aggregate bound together with bitumen, laid hot and compacted with a roller into a solid, flexible surface. It's the standard material for driveways, car parks and roads because it's faster to lay and cheaper up front than concrete, though it generally needs resealing sooner.
Hot mix asphalt (HMA) is manufactured and delivered at around 150–170°C and must be laid and compacted before it cools — it's the standard for driveways, car parks and roads because it compacts into a dense, durable surface. Cold mix asphalt is pre-mixed and workable at ambient temperature, mainly used for pothole patching and small repairs rather than new paving, since it never fully hardens to the same density as hot mix.
| Material | Typical density |
|---|---|
| Hot mix asphalt (HMA) | 2,400 kg/m³ |
| Warm mix asphalt | 2,400 kg/m³ |
| Dense graded asphalt | 2,350 kg/m³ |
| Open graded asphalt | 2,100 kg/m³ |
| Cold mix asphalt | 2,250 kg/m³ |
| Recycled asphalt (RAP) | 1,950 kg/m³ |
These are compacted, in-place densities — cross-checked against multiple independent paving and engineering references. Asphalt is roughly 40–50% denser than gravel or crushed rock, which is why the same volume of asphalt weighs noticeably more.
| Application | Typical compacted thickness |
|---|---|
| Residential driveway | 25–30mm |
| Footpath | 25–40mm |
| Commercial parking lot | 40–50mm |
| Light-traffic road | 40–50mm |
| Heavy-traffic road / highway | 75mm+, often in multiple layers |
Always specify and order asphalt by its finished, compacted thickness — that's the standard convention in every paving spec, and it's what this calculator's depth field expects.
Compacted volume (m³) = Area (m²) × Compacted thickness (m)
Always measure and specify thickness as the finished, compacted depth — that's the standard convention for every paving spec, and it's the figure this calculator's thickness field expects.
Base weight (kg) = Compacted volume (m³) × Compacted density (kg/m³)
Order weight = Base weight × (1 + waste% ÷ 100)
Density listed for each material is the compacted, in-place density — mass per cubic metre of the finished, rolled result. Because density is defined as mass per unit volume at that state, multiplying compacted volume by compacted density already gives the complete, correct mass on its own. No separate volume inflation belongs in that calculation: doing so would double-count the compaction effect, overstating the tonnage by whatever percentage was added. A waste allowance (a few percent, covering genuine spillage and trim losses) is the only legitimate adjustment on top of that base weight.
This calculator also shows an informational loose spread thickness figure — how much thicker a paving crew would initially spread loose asphalt before rolling it down to your specified compacted thickness. That's genuinely useful for a crew on site, but it's shown separately and does not feed into the weight calculation, since the weight is already fully and correctly determined by compacted volume and compacted density.
Standard residential driveways use 25–30mm of compacted hot mix over a prepared crushed rock base — see our Gravel Calculator for the base layer itself, typically 100–150mm of compacted road base underneath.
Commercial parking areas need 40–50mm compacted, sometimes more under areas that see heavy vehicle turning or loading, since concentrated wheel loads stress the surface more than straight-line driving.
Road surfacing thickness varies enormously by expected traffic load and is normally specified in engineering drawings rather than estimated — use this calculator for a planning estimate, but confirm the actual spec with the project engineer before ordering.
5% is a reasonable default, covering spillage and trim losses at edges — a genuinely separate, smaller effect from compaction. It's the only percentage adjustment that should increase the ordered tonnage above the base weight calculated from compacted volume and compacted density.
Rolling compacts loose asphalt into a denser, more durable surface. Because the material's mass doesn't change when it compacts — only its volume does — compaction has no effect on how many tonnes you need to order, provided you're working from the compacted density and compacted thickness, which this calculator does. What compaction does affect is how thick to initially spread the loose material: this calculator shows that figure separately, informationally, so a paving crew knows roughly how much to spread before rolling it down to the specified finished thickness. Proper compaction itself is what gives asphalt its load-bearing strength — under-compacted asphalt fails faster, rutting and cracking well before it should.
Material-only asphalt in Australia typically runs $150–$300 per tonne, well above raw gravel's price per tonne since asphalt is a processed, bitumen-bound product. Full installed driveway pricing (material, labour, base preparation, equipment) is a separate, much higher figure, commonly $55–$95/m² for a standard residential job — this calculator estimates material cost only, not installation.
Australian suppliers sell asphalt by the tonne, delivered hot by specialised insulated trucks. Material-only pricing commonly sits at $150–$300/tonne, with full installed residential driveway pricing around $55–$95/m² as of 2026.
US suppliers commonly quote by the ton or cubic yard, with material costing roughly $40–$80 per ton. A cubic yard of asphalt typically weighs around 2 tons, and covers 65–110 square feet at a 3–5 inch depth.
UK suppliers commonly sell asphalt (tarmac) by the tonne, with dense bitumen macadam and hot rolled asphalt being common specifications for driveways and roads. Confirm the specific mix design with your supplier, since UK terminology for asphalt products differs somewhat from Australian and US conventions.
| Step | Working | Result |
|---|---|---|
| Area | 12m × 4m | 48.00 m² |
| Compacted volume | 48.00 × 0.03m | 1.440 m³ |
| Base weight | 1.440 × 2,400 kg/m³ | 3.456 t |
| Order weight (+5% waste) | 3.456 × 1.05 | 3.629 tonnes |
For reference, the informational loose-spread figure at a 20% allowance would be 36.0mm — how thick a crew might initially spread the loose mix before rolling it down to the 30mm finished result. That figure doesn't change the 3.629 tonnes above; the compacted volume and compacted density already give the complete, correct weight.
Area 800 m², compacted volume 36.000 m³, order weight 90.72 tonnes — 7 truckloads at 15 tonnes per load.
Area 45 m², compacted volume 1.350 m³, order weight 3.40 tonnes.
Area 600 m², compacted volume 24.000 m³, order weight 60.48 tonnes.
A 12m × 4m driveway and an 8m × 1m path together, both at 30mm: combined area 56 m², order weight 4.23 tonnes.
Multiply area by compacted thickness for volume, multiply by the material's compacted density for base weight, then add a waste allowance (commonly 5%) for the amount to order. A 48 m² driveway at 30mm needs about 3.63 tonnes of hot mix.
Take your order volume in cubic metres and multiply by the material's density (2,400 kg/m³ for standard hot mix), then divide by 1,000 for metric tonnes, or 907.185 for US tons.
25-30mm compacted for a residential driveway, 40-50mm for a commercial parking lot or light-traffic road, and 75mm or more (often in layers) for heavy-traffic roads.
2,400 kg/m³ for standard hot mix asphalt is a reasonable default. Use the specific figure for your chosen mix type from the material dropdown, or enter a custom density if your supplier provides one.
Around 2,400 kg per cubic metre for standard hot mix - roughly 40-50% heavier than the same volume of gravel or crushed rock, because asphalt is a denser, bitumen-bound product.
Divide your total tonnage by the truck's capacity - commonly 10, 15, 20 or 25 tonnes for asphalt delivery trucks, larger than typical gravel trucks since hot mix logistics are different.
Material-only asphalt in Australia typically costs $150-$300 per tonne. Full installed driveway pricing, including labour and base preparation, is a separate and much higher figure - commonly $55-$95 per square metre for a standard residential job.
Yes - select the Driveway mode, which shows guidance on typical residential thickness (25-30mm compacted), and enter your driveway's dimensions.
Yes - select the Parking Lot mode for guidance on typical commercial thickness (40-50mm compacted), which is thicker than a residential driveway to handle heavier and more frequent traffic.
Asphalt manufactured and delivered hot (around 150-170°C), which must be laid and compacted before it cools. It's the standard for driveways, car parks and roads because it compacts into a dense, durable, long-lasting surface.
Pre-mixed asphalt that's workable at ambient temperature without heating, mainly used for pothole patching and small repairs rather than new paving - it never fully hardens to the same density as properly compacted hot mix.
5% is a reasonable default, covering spillage and trim losses. It's the only percentage that should increase your ordered tonnage above the base weight calculated from compacted volume and compacted density - compaction itself doesn't add tonnage, since mass doesn't change when material compacts.
Area × compacted thickness gives the finished, compacted volume. Multiplying that by the material's compacted density gives the correct base weight directly - no separate compaction-based volume inflation is needed, since compacted density already represents mass per unit of compacted volume. A waste allowance is then added for genuine spillage and trim losses.
Yes, as a planning estimate - select Road mode. Actual road surfacing specifications vary enormously by traffic load and are normally set by engineering drawings, so confirm the exact spec with the project engineer before ordering.
Yes - densities, thickness guidance and cost ranges reflect Australian conventions and 2026 pricing, alongside general US and UK guidance for international users.
Waste covers material lost to spillage and trimming at edges, and is the only factor that increases ordered tonnage above the base weight. The calculator's loose-spread figure is informational only, estimating how thick to initially spread loose material before rolling - it does not add tonnage, since compacting doesn't change a material's mass, only its volume.
Because that's the finished, in-service thickness that actually matters for the pavement's performance - specifying loose thickness would be meaningless since it changes substantially once rolled. Every paving spec and this calculator's depth field both expect compacted thickness.
A driveway 10 metres long and 4 metres wide paved at 40 mm has an area of 40 m². Volume is 40 × 0.04 = 1.6 m³. Hot-mix asphalt is about 2400 kg/m³, so that’s 1.6 × 2400 = 3840 kg, or 3.84 tonnes. Adding 10% for compaction and wastage gives about 4.2 tonnes to order.
The durability of an asphalt surface depends as much on what’s underneath as on the asphalt itself. A properly compacted road-base foundation — usually 100 mm or more of crushed rock — is essential; asphalt laid over soft or uneven ground will crack, sink and pothole no matter how good the mix is. The base should be graded to drain water away, because trapped water is the main enemy of asphalt longevity. On a solid base, a residential driveway of 25–40 mm of dense-grade hot mix will last for many years.
Timing and compaction matter too. Hot-mix asphalt has to be laid and rolled while it’s still hot, which is why it’s delivered in insulated trucks and worked quickly — this is the main reason larger jobs are best handled by contractors with the right equipment. For small repairs and patching, cold-mix asphalt is available in bags and can be worked by hand, though it’s less durable than hot mix. When ordering, always round up: asphalt is sold by the tonne, a part-load still incurs delivery, and having slightly too much is far better than stopping a pour halfway because you ran out.
The right asphalt thickness depends entirely on what will drive or park on the surface. A residential driveway carrying cars and the occasional delivery van is fine at 25–40 mm of dense-grade hot mix over a good base. Car parks, shared driveways and anything taking heavier or more frequent vehicle traffic need 40–50 mm or more, and commercial or industrial areas thicker still. Going too thin to save on material is a false economy — an underspecified surface cracks, ruts and potholes far sooner, and repairs cost more than the material saved. Because the thickness you enter feeds directly into the tonnage, it’s worth deciding the correct depth for your traffic before ordering, rather than working backwards from a budget.
| Gravel Type | Bulk Density | Common Use |
|---|---|---|
| Pea gravel / river pebbles | ~1.5-1.6 t/m³ | Garden beds, decorative |
| Crushed rock (20mm) | ~1.8-1.9 t/m³ | Driveways, drainage |
| Blue metal (20mm) | ~1.9-2.0 t/m³ | Concrete aggregate, driveways |
| Decomposed granite | ~1.6-1.8 t/m³ | Paths, driveways |
| Road base (compacted) | ~2.0-2.2 t/m³ | Sub-base for driveways |
| Application | Recommended Depth |
|---|---|
| Decorative garden bed | 40-50 mm |
| Landscaping path | 50-75 mm |
| Residential driveway | 75-100 mm over compacted base |
| Drainage layer | 100-150 mm |
How do I calculate how much asphalt I need?
Multiply the area (length × width) by the thickness in metres to get the volume in cubic metres, then multiply by the asphalt density — about 2.4 tonnes per cubic metre for hot mix. This asphalt calculator does it for you and adds a wastage allowance. Asphalt is ordered by the tonne.
How many tonnes of asphalt do I need per square metre?
At a typical 40 mm thickness, one square metre of hot-mix asphalt weighs about 96 kg, so roughly 10.4 m² per tonne. Thicker layers use more per square metre — the calculator shows your exact figure once you enter the thickness.
How thick should an asphalt driveway be?
A residential asphalt driveway is usually laid 25–40 mm thick over a compacted base. Car parks and areas taking heavier vehicles need 40–50 mm or more. Enter your chosen thickness above to get the tonnage.
Is asphalt sold by the tonne or cubic metre?
Asphalt is normally sold and delivered by the tonne. This calculator gives you both the volume in cubic metres and the weight in tonnes so you can order confidently, with a wastage margin included.