How our gravel calculator works

No black box. Every number this site produces comes from the formulas and data below, and you can check any of it against your own supplier's quote.

The core formula

Every gravel calculation is the same three steps. Area, depth, density.

cubic feet  = area (sq ft) × depth (inches) ÷ 12
cubic yards = cubic feet ÷ 27
tons        = cubic yards × density (tons per yd³)

The only place calculators disagree is density. A cubic yard of stone is not a fixed weight — it depends on the material, how angular it is, and how wet it is. We use in-place compacted densities, which is what suppliers quote against.

Densities we use

These come from published aggregate specifications and are consistent with what quarries list on their own material sheets. A cubic yard of gravel weighs between about 2,700 and 3,000 pounds.

Material	Nominal size	Tons per yd³	Lb per yd³
Crusher Run / #411 (base)	0 – 3/4" with fines	1.5	3,000
#57 Crushed Stone (3/4")	3/4"	1.4	2,800
#8 Crushed Stone (3/8")	3/8"	1.4	2,800
#4 Crushed Stone (1.5")	1.5" – 2.5"	1.35	2,700
Pea Gravel (3/8" rounded)	3/8" rounded	1.35	2,700
River Rock (1" – 2")	1" – 2" rounded	1.35	2,700
Decomposed Granite	1/4" and fines	1.4	2,800
Crushed Limestone	3/4" with fines	1.45	2,900
Marble Chips	1/2" – 1"	1.35	2,700
Coarse / Bedding Sand	Fine	1.35	2,700

Where our prices come from

Prices are 2026 national averages for bulk material delivered within a normal haul radius, given as a low-to-high range rather than a single figure. Regional variation in aggregate is large — the same stone can differ by 60% between a region with local quarries and one without — so treat the range as a sanity check on a quote, not a substitute for one.

Delivery is modelled separately, as a flat fee per truck load rather than per ton, because that is how suppliers actually bill it. That is why our delivery calculator flags when your order leaves a truck half empty.

Waste and compaction

Gravel settles. Angular stone locks together and loses volume under a compactor, and some material always works into the subgrade on the first pass. Our default allowance is 10%, which matches standard practice. Over soft or wet ground, 15% is more realistic.

This is the single most common reason a DIY order comes up short: the arithmetic was right, but it was done on the finished depth with no allowance for what compaction takes away.

What we deliberately do not model

Your subgrade. Soft clay may need a deeper base or a geogrid. No calculator can see your soil.
Slope and erosion. Steep driveways need coarser stone and drainage design, not just more depth.
Local code. Some jurisdictions restrict gravel driveways or require a paved apron at the road.
Haul distance. Beyond a supplier's normal radius, delivery can exceed the material cost.

Rounding

We round volumes to two decimals and costs to the nearest dollar. Suppliers generally sell in half-ton or full-yard increments, so round your final order up to whatever your quarry sells in — running short mid-job costs another delivery fee.