Gravel Calculator: Tons, Yards & Cost

Gravel calculator: cubic yards, tons, and compaction buffer

This calculator estimates gravel volume from area × depth, converts to cubic yards and tons using material density, and optionally adds a 12% compaction buffer for settling. Material and haul only; no labor or delivery fees.

What this calculator does

The widget computes gravel volume for rectangular, circular, or triangular areas from your dimensions and depth, converts to cubic yards and cubic meters, then estimates weight in tons (and pounds) using preset or custom material density. An optional 12% compaction buffer adds spare volume for settling under traffic and rain. Optional price per ton gives a rough material subtotal in the results panel. It does not price delivery, base excavation, geotextile, edging, or compaction equipment.

Rectangular volume:

$V = L \times W \times D$
Circular (radius r):

$V = \pi r^2 \times D$
Triangular:

$V = \frac{1}{2} \times b \times h \times D$
Weight:

$\text{tons} = \frac{\text{yd}^3 \times \text{lbs/yd}^3}{2000}$

How the math works

Start with the default rectangular inputs: 10 ft × 10 ft and depth 3 in (0.25 ft). The widget multiplies to get 25 ft³, divides by 27 for about 0.93 yd³ net, then applies the 12% compaction buffer to show 1.04 yd³ in the results headline. With crushed stone at 2,700 lb/yd³, weight is about 1.40 tons (~2,800 lb).

For a driveway strip, enter 20 × 10 ft at 4 in deep with the same material and buffer. Volume becomes 66.7 ft³ → 2.77 yd³ to order and roughly 3.73 tons. Circular pads use radius (not diameter): 5 ft radius at 3 in depth yields about 0.81 yd³ and 1.10 tons with the buffer on.

Triangular areas use ½ × base × height × depth before the same ÷ 27 conversion. If your quarry ticket lists a density outside the presets, choose Custom Density and enter lbs/yd³—the weight lines in the results panel update while volume stays the same.

Limits of the model

Crushed stone compacts and interlocks for driveways; pea gravel suits paths but moves under vehicle tires; river rock is heavy for beds; sand suits bedding. The widget does not pick product for you—match stone to subgrade and load with your supplier. Depth guidance, buffer size, and density presets are planning estimates; wet stone, voids, and truck minimums can change what you actually order.

FAQ

How many tons of gravel are in a cubic yard?

It depends on the stone. The Gravel Type dropdown in Project dimensions uses typical dry densities: pea gravel about 2,600 lb/yd³ (~1.3 tons), crushed stone 2,700, river rock 2,900, sand 2,800. Wet or dirty loads weigh more. If your quarry prints a number on the ticket, choose Custom Density and enter lbs per cubic yard.

How much gravel do I need for a driveway?

Pick Rectangular, enter pad length and width in feet, and set Depth to finished thickness after compaction. Residential driveways usually want 4–6 inches of crushed stone (3 inches is a bare minimum). Leave the 12% compaction buffer enabled for traffic areas.

What is the compaction buffer for?

The checkbox adds 12% spare volume (on by default) so you still hit target depth after traffic and rain squeeze air out. The widget multiplies cubic yards after ÷ 27, before weight. Skimp here and you expose the base before the season ends.

Which gravel works on a sloped driveway?

Crushed stone with angular edges locks together when compacted. Pea gravel rolls under tires on a grade. For steep pitches, use larger aggregate (around 1–2 in), keep drainage off to the side, and compact in lifts. Material choice is a preset in the widget only—it does not change volume math.

Why does my quote list tons but I measured yards?

Quarries price and load by weight; you measure by area and depth. The results panel converts with density: tons = cubic yards × lbs/yd³ ÷ 2,000. Enter optional Price per Ton to compare material subtotals on the same job (delivery not included).

Does the circular shape use radius or diameter?

The Radius field is center to edge, not diameter. At 5 ft radius and 3 in depth with crushed stone and the 12% buffer, the widget shows about 0.81 yd³ and 1.10 tons. Double-check before ordering round beds or culvert pads.

How does the triangular shape work?

Choose Triangular in the shape dropdown, then enter Base, triangle Height (the altitude perpendicular to the base—not depth), and Depth of gravel. Volume = ½ × base × height × depth, then the same ÷ 27 and buffer steps as other shapes.

What does depth mean in this calculator?

Each shape’s Depth field is finished gravel thickness after compaction, not the height of a loose pile before tamping. Walkways often finish at 2–3 in of pea gravel; driveway bases run 4–6 in after compaction.

Gravel Calculator

Project dimensions

How to use this calculator

Reading volume, weight, and order quantity

Worked scenarios

Example: 10 × 10 ft pad, 3 in deep (default rectangular)

Example: 20 × 10 ft driveway strip, 4 in deep

Depth field = finished thickness

Custom Density preset on the ticket