Aggregate & Base · Complete Guide

Aggregate & Base Material Calculators

Eight calculators for the sub-surface materials that carry every driveway, foundation, and structure — gravel, crushed stone, road base, fill dirt, sand, and topsoil.

Why Base Material Matters More Than the Surface

Every durable paved surface — asphalt, concrete, pavers, gravel — is only as strong as the aggregate base beneath it. The surface material (asphalt, concrete) gets all the attention but the base does the actual load-carrying work.

A 4-inch asphalt drive over 6 inches of properly compacted aggregate base lasts 20 years. Same 4-inch asphalt over 2 inches of loose fill fails in 3-5 years with alligator cracking, potholes, and surface rutting. Base isn't a corner to cut.

This cluster covers all eight base-material calculations:

  • Gravel & crushed stone — the family of crushed aggregates
  • Road base / base rock — dense-graded compactable sub-base
  • Fill dirt — structural grading material
  • Sand — bedding and leveling layer
  • Topsoil — the final growing layer

8 Aggregate Calculators in This Cluster

Organized by material type — from compactable base rock to garden-grade topsoil.

Gradation: The Key Variable Most Homeowners Skip

Aggregate products are defined by their gradation — the distribution of particle sizes, from dust to largest stone. Gradation determines whether material compacts, drains, or stays stable under load.

Two gradation families:

  1. Uniformly graded (e.g., #57 stone, #2 stone, pea gravel) — all particles similar size. Open voids. Drains freely. Does not compact into a solid mass.
  2. Dense-graded (e.g., crusher run, DGA, Class 5, road base) — full range from dust to maximum size. Minimal voids. Compacts into a solid structural base at 95%+ Proctor density.

Practical rule:

  • For drainage → uniformly graded stone (voids carry water)
  • For structural base → dense-graded base rock (compacts solid)
  • For decorative surface → pick by color and shape, gradation secondary

Mixing them up is the #1 DIY aggregate mistake. #57 stone looks great in a driveway until the first rainy week when it shifts and spreads everywhere.

Density, Compaction & Coverage Reference

Four numbers to know for every aggregate:

  • Loose density: as delivered — 75-110 lb/ft³ range
  • Compacted density: after rolling — 10-15% higher than loose
  • Tons per cubic yard: density × 27 / 2,000
  • Coverage at X inches: for ordering by area

Quick conversion table at 100 lb/ft³ average:

  • 1 cubic yard = 27 cubic feet = 1.35 tons
  • 1 cubic yard covers 108 ft² at 3 in deep, 81 ft² at 4 in deep, 54 ft² at 6 in deep
  • 1 ton covers 80 ft² at 3 in, 60 ft² at 4 in, 40 ft² at 6 in
Aggregate Quick Picker by Application
ApplicationBest ProductDepthDensity Assumption
Driveway top layer (decorative)Pea gravel or #57 stone2-3 in95-100 lb/ft³
Driveway structural baseRoad base / DGA4-6 in110 lb/ft³
Concrete slab sub-base#57 stone4 in100 lb/ft³
Paver patio baseDGA + 1 in stone dust4 in110 lb/ft³
French drain fill#57 or #4 stone12+ in95-100 lb/ft³
Retaining wall drainage#57 stone (behind wall)12 in100 lb/ft³
Yard leveling / gradingScreened fill dirtVaries90 lb/ft³
New lawn topsoilScreened topsoil4-6 in75 lb/ft³
Raised garden bedPremium garden mix8-12 in75 lb/ft³
SandboxPlay sand (washed)6-8 in95 lb/ft³
Paver beddingPaver sand (coarse)1 in100 lb/ft³

Use this table to pick the right calculator and default density for your project.

2026 Bulk Aggregate Pricing
MaterialPrice/ton at QuarryDelivered Price/yd³Typical Delivery Minimum
Fill dirt (screened)$8-18$15-3510 yd³
Topsoil (screened)$14-28$22-428 yd³
Premium garden mix$35-55$45-656 yd³
Pea gravel$28-45$40-6010 yd³
#57 stone$22-35$35-5010 yd³
DGA / crusher run$18-28$30-4210 yd³
Base rock (West Coast)$26-38$40-5810 yd³
Concrete sand$28-42$40-5810 yd³
Paver bedding sand$32-48$48-685 yd³

Larger tonnage orders (30+ tons) may qualify for reduced per-ton pricing. Negotiate on bulk orders. Minimum deliveries typically one full truck load.

Aggregate & Base Material Calculators — workflow diagram
Aggregate & Base Material Calculators — workflow diagram

The Excavation-to-Surface Workflow

  1. Excavate — remove organic material (grass, roots, topsoil) to a depth that accommodates the base + surface stack. Typically 8-12 in for driveways.
  2. Compact subgrade — roll or plate-compact the exposed soil to 90%+ Proctor. Prevents future settling.
  3. Geotextile (optional but recommended) — fabric layer prevents soil and aggregate from mixing. Adds $0.30-0.60 per ft². Critical on clay soils.
  4. Base aggregate — place dense-graded base rock in 4-6 in lifts; compact each lift with plate or roller.
  5. Leveling layer — 1 in of sand or stone dust for paver applications; skip for concrete or asphalt.
  6. Surface material — asphalt, concrete, pavers, or gravel top course.

The order is non-negotiable. Skipping compaction between layers causes layer migration and base failure within 2-3 years.

For a deeper walk-through of driveway-specific layering with thickness recommendations for clay, sandy, and rocky subgrades, see our complete driveway base layers guide.

If the goal is a complete driveway rather than one aggregate order, use the gravel driveway project path to connect excavation, geotextile, road base, surface gravel, and drainage.

Real-World Example Calculations

Complete Driveway Material Breakdown: 12 × 50 ft

New gravel driveway from scratch, with proper base prep.

Excavation
12 × 50 × 12 in = 22 yd³ removed
Geotextile fabric
600 ft² = $210
Road base
12 × 50 × 6 in = 16.5 tons @ $22 = $363
Top gravel (#57)
12 × 50 × 3 in = 8.25 tons @ $28 = $231
Total Material Cost $804 + delivery

Takeaway: Typical material cost for a quality 600 ft² gravel driveway. Labor and equipment add $2,000-3,500 if hired; DIY brings total to ~$1,000-1,500.

Engineering References

These references are used for terminology, safety boundaries, and engineering assumptions. Local code, supplier specifications, and licensed design documents still control your project.

  1. ASTM D448: Standard Classification for Sizes of Aggregate ASTM International

    Referenced for crushed stone and aggregate size classifications.

  2. ASTM C33/C33M: Standard Specification for Concrete Aggregates ASTM International

    Referenced for concrete aggregate grading and quality terminology.

  3. USGS National Minerals Information Center U.S. Geological Survey

    Referenced for aggregate, sand, stone, and mineral commodity context.

  4. FHWA Geotechnical Engineering Program Federal Highway Administration

    Referenced for subgrade, compaction, and soil support concepts.

Frequently Asked Questions

What's the difference between gravel and crushed stone?

Gravel is naturally rounded stone from riverbeds. Crushed stone is quarried and mechanically broken, producing angular faces. Crushed stone compacts denser (~95% Proctor); gravel tops out at ~85%. For structural applications, always specify crushed stone.

How do I calculate aggregate tonnage?

Multiply length × width × depth (all in feet), multiply by material density (lb/ft³), divide by 2,000 for tons. For 100 lb/ft³ material, a shortcut: ft³ × 0.05 = tons.

What's the best gravel for a driveway?

Two-layer approach: 4-6 inches of road base / DGA for the structural sub-base (compacted), 2-3 inches of #57 or pea gravel for the driving surface. Single-layer driveways with only decorative gravel fail within 1-2 years under vehicle loads.

How much does aggregate cost delivered?

Residential deliveries in 2026: $35-65 per cubic yard delivered for standard crushed stone. Fill dirt $15-35. Topsoil $22-42. Premium garden mix $45-65. Add $60-150 per load in trucking fees on top of per-yard pricing.

Can I compact gravel with a car?

Partially — driving back and forth compresses the top layer to ~85% density, adequate for low-use applications. For structural driveways and under pavement, rent a plate compactor ($60/day) or vibratory roller ($350/day). Proper compaction extends the life of any surface placed on top by 5-10 years.

How much aggregate do I need for a 10x20 ft driveway?

At 6 inches compacted road base + 2 inches #57 top layer: ~8 tons of road base + 2.5 tons of #57 for a 200 ft² driveway. Small projects have higher per-ton trucking costs — consider splitting a load with a neighbor.

Do I need a weed barrier under gravel?

Yes for landscape applications and decorative gravel paths. Landscape fabric prevents weeds from growing up through the gravel and keeps gravel from sinking into soil. For driveways and structural applications, use geotextile fabric instead — heavier duty, prevents clay migration up into the base.