Gravel Calculator

Different gravel types serve different purposes and have different densities. Crushed stone (angular pieces from blasted rock) compacts well and locks together — good for driveway bases, walkway sub-surfaces, and structural applications. Pea gravel (small, rounded river-stone) doesn't compact and stays loose — good for decorative beds, drainage, but not for surfaces that need stability.

Common types: 3/4-inch crushed stone (driveway base), 3/8-inch washed (decorative, walkways), pea gravel (drainage, beds), road base (graded mix designed to compact tightly), river rock (decorative, larger sizes). Quarry suppliers can be specific — call ahead to confirm availability and pricing for the type and quantity you need.

Gravel weighs roughly 2,500–3,000 lbs per cubic yard depending on type, moisture content, and packing density. Common conversions: 3/4-inch crushed stone ≈ 2,700 lbs/cu yd, pea gravel ≈ 2,800 lbs/cu yd, road base (compacted) ≈ 3,000+ lbs/cu yd, river rock ≈ 2,800–3,000 lbs/cu yd.

1 ton ≈ 0.74 cubic yards for typical crushed stone. For ordering: a quarry may quote you 5 tons; that's about 3.7 cubic yards spread out. Your project, calculated in cubic yards, multiplies by ~1.35 to get tons for ordering.

Driveway: typically a 4-6 inch base of road base or larger crushed stone, topped with a 2-3 inch layer of finer surface gravel. A 12-foot × 50-foot driveway with 6 inches of base + 3 inches of surface needs 600 sq ft × 0.75 ft = 450 cu ft = 16.7 cu yd of base (and 8.3 cu yd of surface, scaled by depth).

Walkway: 3–4 inches typically suffices. Less subject to vehicle weight, so the structural requirement is lower.

Drainage (French drain, gravel bed): pea gravel or 3/8-inch washed, in a trench typically 12–24 inches deep wrapped in landscape fabric.

Decorative beds: 2–3 inches deep, usually pea gravel or river rock. Landscape fabric beneath is essential — without it, the gravel sinks into the soil and weeds emerge through it within months.

Gravel compacts substantially when packed — a 6-inch loose-poured layer might compact to 4–5 inches under traffic and tamping. For driveway bases especially, plan for the loose volume, then tamp or roller-compact the layers as you build up. Compaction is what makes a gravel driveway last 10+ years instead of rutting after a few months.

Ordering: round up to the supplier's standard delivery size (usually whole or half tons). A calculation showing 4.3 tons should be ordered as 4.5 or 5 tons — the half-ton extra is cheap insurance against running short, and small leftovers can fill low spots, line garden beds, or be saved for repairs.