What this Driveway Gravel & Road Base Calculator does

Planning a new gravel driveway or topping up an old one? This driveway gravel calculator estimates everything you need in minutes—volume (m³/yd³), weight (tonnes/tons), cost and truck loads—for up to three layers (sub-base, base and top course). It supports rectangle or tapered driveways, metric/imperial units, compaction and waste so your order reflects real-world delivery, not just neat math. Use it to price road base, crushed rock, decomposed granite or pea gravel, and to plan extras like geotextile underlay and edging. (Always follow local specs or an engineer’s guidance.)

How to use the calculator (step-by-step)

1. Pick units & shape
   Choose Metric (m, cm, m³, tonne) or Imperial (ft, in, yd³, ton), then choose Rectangle or Tapered (two different widths).
2. Enter driveway dimensions
   • Rectangle: Length × Width
   • Tapered: Length, Width at start, Width at end (area uses the average width)
3. Set compaction & waste
   • Compaction factor (typical 1.10–1.20) inflates compacted volume to the loose volume delivered.
   • Waste % adds a small buffer for over-excavation, offcuts and spillage.
4. Configure up to 3 layers (Sub-base, Base, Top)
   • Depth per layer (cm or in)
   • Material (preset densities you can edit)
   • Price either per tonne/ton or per m³/yd³
5. Truck size & currency
   Enter your truck’s capacity (e.g., 10 t per load) to see estimated loads, and set your currency symbol.
6. Calculate
   See compacted vs loose volume, tonnes/tons, cost per layer & total, loads, plus area & perimeter for geotextile/edging planning. Adjust inputs until the totals match your budget.

Pro tips

• Place geotextile under sub-base to reduce pumping and mixing with subgrade.
• Order materials per layer if your supplier will stage deliveries; it reduces on-site mixing and guesswork.
• For tidy edges and less spread, add edging or a low shoulder berm.
• Confirm local council specs (depths, materials) and drainage requirements before ordering.

FAQ: Driveway gravel, road base & costs

What depths should I use for a gravel driveway?
For light-duty domestic driveways, a common build is sub-base 100–150 mm (4–6 in), base 75–100 mm (3–4 in) and top course 25–40 mm (1–1.5 in). Softer soils, slopes and vehicle loads may require more—follow local specs or an engineer.

What is the compaction factor and why does it matter?
Gravel and road base compact on the ground. A compaction factor (e.g., 1.15) converts compacted volume into the loose volume you need to order. The calculator shows both so you don’t under-order.

Which material density should I use?
Densities vary by quarry and gradation. Presets in the tool give typical compacted values for road base, crushed rock, decomposed granite, pea gravel and recycled concrete. Your supplier can provide an exact figure—just overwrite the preset.

How do I estimate cost accurately?
Enter your supplier’s price per tonne/ton or per m³/yd³ for each layer. The calculator multiplies the correct unit by your layer’s loose volume or weight and totals it across layers, including your waste and compaction settings.

How many truck loads will I need?
Set your truck size (e.g., 10 t per load). The tool converts each layer’s requirement into loads and rounds up. It also totals loads across layers so you can schedule deliveries.

Rectangle vs tapered—what’s the difference?
Tapered driveways use Length with two widths (start and end). The calculator uses the average width to compute area, which is appropriate for straight tapers.

Do I need geotextile under a gravel driveway?
On soft or clayey subgrades, a non-woven geotextile below the sub-base helps stop fines from pumping up and mixing with the aggregate. Order at least the driveway area plus overlaps; the calculator’s area output is a good starting point.

Can I use recycled concrete or asphalt millings?
Often yes—recycled concrete (RCC) can perform similarly to crushed rock for sub-base/base layers when well graded and compacted. Check local availability and specs; density/cost may differ.

Will the calculator include edging or drainage?
It reports area and perimeter to help you plan edging length and geotextile. Drainage (ditches, pipes, crowns) is site-specific; follow local guidance.

Why do my numbers differ from a supplier’s quote?
Suppliers may use different densities, lift thicknesses or include minimum load fees and delivery zones. Share your inputs with them; they can adjust density/price to match their product.