TryBuildCalcDouble-Car Asphalt Driveway Calculator (20-24 ft Wide)
Size your double-car asphalt driveway instantly.
🕒 Last updated: September 8, 2026
Inputs
ℹ️L-Shaped models a main run plus a second connected section — an apron, turn, or widened area — as two rectangles added together.
ℹ️Distance from the street/curb to the garage or parking area.
ℹ️Single-car driveways are typically 10-12 ft wide; double-car driveways are typically 20-24 ft.
Aggregate Base
ℹ️6 in is standard for residential driveways; go to 8 in for soft soil or heavy vehicles.
ℹ️Standard dump trucks carry around 10-12 tons per load. Applies to both the aggregate base and the asphalt delivery.
Asphalt
Asphalt Institute residential guidance describes a 2-lift build (a 2 in binder course plus a 1.5 in surface course, bonded with a tack coat) that can give a well-designed driveway up to 20 years of service. A single 2.5-3 in lift is the more common budget install, with a shorter expected service life.
ℹ️The binder course uses a coarser, structural dense-graded mix — SMA is a specialized surface/wearing-course product, not normally used for binder.
ℹ️A tack coat is applied between the binder and surface courses to bond them — required for two-lift construction, computed automatically below.
ℹ️The surface course uses a finer mix for a smooth, driveable top — can be the same or a different mix than the binder course.
Geotextile Fabric, Edging & Sealcoat
Site-dependent, not universal — FHWA guidance generally prefers dense-graded aggregate alone on a competent, well-drained subgrade; fabric is more applicable to weak, sensitive, wet, or high-fines subgrade conditions.
Purely an aesthetic/erosion-control add-on for asphalt — unlike interlocking pavers, a poured asphalt mat doesn't need an edge restraint structurally.
A post-installation maintenance step, not part of the initial build — new asphalt needs 6-12 months to cure before its first sealcoat application.
Cost
Total Asphalt Needed
9.137 tons
2-lift (binder + surface)
Total Material Weight
23.481 tons
Base + asphalt combined
Area
400 sq ft
20 × 20 ft
Aggregate Base
Quarry Process (QP) — US driveway base, 6" deep
Installed volume: 7.41 cu yd
Order volume (incl. 15% compaction + 8% waste): 9.2 cu yd
Weight: 14.344 tons
1 full (10t each) + 1 partial (4.34t)
Binder Course
Standard Dense-Graded Hot-Mix Asphalt (HMA), 2" deep
Order volume (incl. 8% waste): 2.67 cu yd
Weight: 5.221 tons
1 partial delivery: 5.22t (truck capacity 10t)
Surface Course
Standard Dense-Graded Hot-Mix Asphalt (HMA), 1.5" deep
Order volume (incl. 8% waste): 2 cu yd
Weight: 3.916 tons
1 partial delivery: 3.92t (truck capacity 10t)
Tack Coat
Bonds binder to surface course
Tack coat needed: 2.44 gal
Typically contractor-applied, not a retail DIY purchase.
Assumptions Used
Standard US residential asphalt driveway, rectangular or L-shaped, built as a compacted aggregate base topped with hot-mix asphalt — either a single lift, or two lifts (a binder course plus a surface course bonded with a tack coat), per Asphalt Institute residential guidance. Binder and surface courses can use different mix types, matching real gradation differences between the two. Truck loads for two-lift construction are calculated per lift (binder and surface each independently, then totaled), since they're placed as separate deliveries. The aggregate base uses a 15% compaction allowance and 8% waste, matching the site's general gravel-weight calculator. Asphalt tonnage is calculated directly from the target COMPACTED thickness x density plus an 8% waste allowance (spillage/truck residue) — no separate compaction allowance, since asphalt is compacted by roller during paving rather than settled from a loose delivered pile. Tack coat (two-lift only) uses a 0.05 gal/sq yd application rate plus 10% waste. Geotextile fabric (off by default — site-dependent, see FHWA guidance) area includes a 10% overlap allowance for seams; standard roll size is 12.5 × 360 ft. Sealcoat (optional, off by default since it is a post-installation maintenance step) uses an 80 sq ft/gallon coverage rate per coat. Edging length sums each section's own full perimeter — for L-shaped mode this is a conservative over-estimate. This calculator computes material quantities only — it does not verify subgrade compaction adequacy, local drainage requirements, or structural design for unusual soil or loading conditions.
Bill of Materials
Main material: 14.344 tons + recommended tools
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Bill of Materials
Main material: 14.344 tons + recommended tools
Computed items reflect your entered dimensions and layer choices; consumables below are general recommendations — actual needs vary by product and site conditions.
For Your Job
Aggregate Base
Binder Course
Surface Course
Tack Coat
General Tools & Consumables
Landscape stakes / fabric pins
Plate compactor or roller
Tack coat sprayer
Lute / rake (asphalt-grade)
Sealcoat squeegee or sprayer
Edging stakes or forms
String line / grade stakes
Tape measure
Safety glasses, work gloves & heat-resistant boots
Diagram simplified for clarity (not to scale) — layer thicknesses shown proportionally, footprint shown schematically.
Looking for the verification checklist, reference tables, tips, or common mistakes?See the complete Asphalt Driveway Calculator.
Double-car asphalt driveway material takeoff
A double-car asphalt driveway is typically 20-24 ft wide, sized to fit two vehicles side by side.
This page defaults to a 20 ft × 20 ft footprint — edit the inputs above to match your actual driveway.
Asphalt Driveway Calculator Formula: How Is It Determined?
Each layer is calculated using its own real construction logic, then combined into one material takeoff.
Step 1 — Aggregate Base
Volume = Area x Base Depth
Weight = Volume x (1 + 15% compaction) x Material Density x (1 + 8% waste)
The base is delivered loose and compacted in place, so it gets the same 15% compaction and 8% waste allowances used across the site's driveway calculators.
Step 2 — Asphalt (Single-Lift or Two-Lift)
Volume = Area x Lift Depth
Weight = Volume x Mix Density x (1 + 8% waste)
No compaction allowance — asphalt tonnage is calculated directly from the target COMPACTED thickness, since it's compacted by roller while still hot during paving. Two-lift mode computes the binder course and surface course separately (each can use a different mix type), and calculates each lift's own truck loads independently before totaling — they're placed as separate deliveries.
Step 3 — Tack Coat (Two-Lift Only)
Gallons = (Area / 9) x 0.05 gal/sq yd x (1 + 10% waste)
Bonds the binder course to the surface course so traffic loads are carried by the full structure — computed automatically whenever two-lift construction is selected, never for single-lift.
Step 4 — Fabric, Edging & Sealcoat
Fabric Rolls = ceil(Area x (1 + 10% overlap) / Roll Area)
Sealcoat Gallons = (Area x Coats) / 80 sq ft per gallon
Fabric (optional, off by default — site-dependent, see FHWA guidance) is priced per whole roll actually purchased. Sealcoat (optional, off by default) is a post-installation maintenance step — new asphalt needs 6-12 months to cure before its first application.
Worked Example
This example walks through your current inputs above, using the same steps as the Formula section.
Input Values Used
| Input | Value | Why it is used |
|---|---|---|
| Shape | 20 ft / 20 ft | Sets area for every layer |
| Construction | 9.5" total (6" base + 2" binder + 1.5" surface) | Sets volume and weight per layer |
| Fabric / Edging / Sealcoat | Not included / Not included / Not included | Sets add-on quantities |
Step 1 — Aggregate Base
| Calculation | Result |
|---|---|
| Volume = 400 sq ft x (6/12) ft | 200 cu ft (7.41 cu yd) |
| Weight = Volume x (1 + 15%) x density x (1 + 8%) | 14.344 tons |
| Truck loads = ceil(14.344 / 10) | 2 loads |
Step 2 — Asphalt
| Calculation | Result |
|---|---|
| Binder = 400 sq ft x (2/12) ft x density x (1 + 8%) | 5.221 tons |
| Binder truck loads = ceil(5.221 / 10) | 1 loads |
| Surface = 400 sq ft x (1.5/12) ft x density x (1 + 8%) | 3.916 tons |
| Surface truck loads = ceil(3.916 / 10) | 1 loads |
| Total asphalt = binder + surface (2 separate deliveries) | 9.137 tons, 2 loads total |
Step 3 & 4 — Tack Coat, Fabric, Edging & Sealcoat
| Calculation | Result |
|---|---|
| Tack coat = (400 sq ft / 9) x 0.05 gal/sq yd x (1 + 10%) | 2.44 gal |
Therefore, this 20 ft x 20 ft asphalt driveway needs approximately 14.344 tons of aggregate base and 9.137 tons of asphalt (two-lift), 2.44 gal of tack coat.
Disclaimer: This calculator provides approximate results for planning and estimation purposes only. Actual requirements may vary based on site conditions, materials, workmanship, and local building regulations. Always consult a qualified engineer, architect, or construction professional before making final decisions.