Introduction
I’m Adrian Cole, Construction Cost Analyst. This paver base calculator is for quick planning of crushed stone base under patios, walks, and driveways. Units are imperial (ft, in, tons). Results are planning estimates—validate with project drawings, specs, and supplier quotes.
Scope & Assumptions
- Material: compactable granular base (e.g., 3/4" minus). Density assumed at 21.6 cubic feet per ton.
- Area: rectangular footprint measured in feet.
- Depth: compacted thickness in inches (typical 4–6 in; use project spec).
- Excludes: bedding sand, pavers, edging, geotextile, excavation swell/shrink, haul loss.
- Rounding: report to 0.1 tons; round up when ordering.
Inputs (Calculator-Ready)
- length (ft): run dimension. Default planning range: 4–100 ft.
- width (ft): perpendicular dimension. Default planning range: 2–40 ft.
- depth (in): compacted base thickness. Typical: patios 4–6 in; light driveways 6–8 in; heavy duty 8–12+ in.
Formulas (Validated)
- area = length * width
- depth_ft = depth / 12
- volume_cuft = area * depth_ft
- tons_needed = volume_cuft / 21.6
Worked Example
Patio: 20.0 ft × 10.0 ft × 4.0 in
area = 20.0 * 10.0 = 200.0 ft²
depth_ft = 4.0 / 12 = 0.333 ft
volume_cuft = 200.0 * 0.333 = 66.7 ft³
tons_needed = 66.7 / 21.6 = 3.1 tons
Order at least 3.1 tons. Practically, round up to 3.5–4.0 tons to cover waste and grading variances.
Production & Waste Notes
- Waste/overage: add 5–10% for shaping, loss, and underestimation. Tight access or variable subgrade may push to 10–15%.
- Compaction: thickness is after compaction. If placing loose lifts, account for 10–15% shrink on compaction.
- Delivery: many suppliers sell by ton with minimum loads; confirm truck capacity and delivery zones.
Sanity Checks
- Benchmark: 100 ft² at 4 in depth → about 1.9 tons. If your result for similar size deviates heavily, recheck inputs and units.
- Unit traps: depth must be inches; length/width in feet. Don’t input inches into the feet fields.
Cost Snapshot (Planning)
- Base material: $25–$55 per ton depending on region and gradation.
- Example cost: 3.1 tons × $40/ton ≈ $124. Delivery, fuel surcharges, and tax are extra.
Limitations & Pitfalls
- Irregular shapes: break into rectangles or compute area separately, then apply the same formulas.
- Subgrade variability: soft spots increase thickness—budget extra.
- Double-counting: don’t include bedding sand or pavers in base thickness.
Result/Wrap-Up
Define area and compacted base depth, compute tons via the formulas above, then add reasonable overage and confirm with your supplier. Separate direct material from delivery and markups. Use this as a baseline; field conditions drive the final quantity.