Gravel & Crushed Stone Calculator
Calculate exact gravel tonnage, cubic volume, and material loss from mechanical compaction. Configured for driveway base stone, French drain drainage aggregate, and walkway crushed stone.
Project Dimensions & Aggregate Type
Tonnage & Quarry Takeoff
Subgrade, Geotextile & Compacted Aggregate Strata
Cross-sectional representation showing the mechanical compaction allowance, stabilized subgrade, and recommended geotextile barrier preventing sub-base mud migration.
Gravel Tonnage & Compaction Formulas
Quarries sell aggregate by weight (US short tons = 2,000 lbs), while construction blueprints specify loose cubic volume and compacted in-place depth. Converting geometric volume to quarry purchase tonnage requires accounting for in-situ bulk density $\rho$, mechanical vibratory compaction shrinkage $C_f$, and subgrade interlock waste $W_f$:
V_{\text{loose}} = \frac{\text{Surface Area (sq ft)} \times \left( \frac{\text{Depth (inches)}}{12} \right)}{27}
2. Factored Order Volume with Compaction & Subgrade Allowance:
V_{\text{order}} = V_{\text{loose}} \times (1 + C_f) \times (1 + W_f)
\text{Where } C_f = 0.15 \text{ for plate-compacted crusher run, and } W_f = 0.10 \text{ on native subgrade.}
3. Total Tonnage Conversion:
\text{Tons} = V_{\text{order}} \times \rho_{\text{aggregate}} \quad \text{where } \rho \in [1.30, 1.55] \text{ tons/yd}^3
4. Dump Truck Load Sizing:
N_{\text{Tandem}} = \left\lceil \frac{\text{Tons}}{12} \right\rceil, \quad N_{\text{Tri-Axle}} = \left\lceil \frac{\text{Tons}}{18} \right\rceil
5 Critical Gravel Driveway & Drainage Pitfalls
1. Dumping Gravel Directly onto Mud Without Geotextile
Aggregate has high compressive strength but zero tensile strength. Vehicle axle loads push coarse gravel downward while soil pumps upward into the voids. Within two wet seasons, 50% of your gravel will disappear into subsoil mud. Always install a heavy-duty woven geotextile fabric beneath driveway base stone.
2. Using Rounded Pea Gravel on Vehicular Driveways
Pea gravel consists of smooth, water-worn stones with zero angular edges. Under vehicle tires, pea gravel acts like ball bearings—it shifts laterally, forms ruts, and prevents tires from achieving traction. Driveways require angular, crushed aggregate (#57 or Crusher Run) whose sharp fractured faces mechanically interlock.
3. Ignoring Mechanical Compaction Shrinkage
Crusher Run / DGA contains fine stone dust that fills voids between larger 3/4" stones. When compacted with a heavy reversible plate compactor or vibratory roller, the in-place volume decreases by 15% to 20%. Ordering exact loose volume results in an installed depth 1 to 2 inches too thin.
4. Failing to Crown the Center of the Roadway
A flat gravel driveway is doomed to develop potholes. Standing water softens the aggregate matrix, allowing traffic tires to scour out stone dust. Grade the center with a 1/2" per foot crown slope (a 12-ft driveway should be 3 inches higher at the center crown than at the edges) to shed runoff into side swales.
5. Woven vs Non-Woven Fabric Misapplication
Woven geotextile offers high tensile separation and load distribution, making it perfect for driveways and road bases, but has a low water flow rate. Non-woven needle-punched geotextile (felt-like) has high permeability and is mandatory for French drains and dry wells. Installing woven fabric in a French drain will cause it to clog and flood.