#2 Stone Calculator

How much #2 stone do I need?

This #2 stone calculator finds the tons of stone for a pad or bed with one formula: length × width × (depth in inches ÷ 12) ÷ 27 gives cubic yards, and cubic yards × 1.4 gives tons. A 20 ft × 10 ft construction entrance at 6 inches deep needs 5.19 tons, or 5.70 tons with the 10% waste box ticked.

Enter the length and width in feet, the loose depth in inches, and your quarry’s price per ton. The result shows tons to order and the estimated cost.

The formula in plain words

#2 stone is sold by the ton but placed by volume, so the calculator makes two conversions:

1. Volume: length × width × depth in feet gives cubic feet. Dividing by 27 turns cubic feet into cubic yards, because one cubic yard is 3 ft × 3 ft × 3 ft.
2. Weight: cubic yards × 1.4 tons per cubic yard gives tons. That 1.4 figure is a typical loose, dry weight for clean stone this size.
3. Waste (optional): tons × 1.10 when the 10% box is ticked.
4. Cost: tons × price per ton.

Large clean stone has big voids between pieces and does not compact much, so the depth you enter should be the finished depth you want, not a compacted target.

Worked examples

1. Default pad: 20 ft × 10 ft × 6 in, $45/ton

• Cubic feet: 20 × 10 × 0.5 = 100 ft³
• Cubic yards: 100 ÷ 27 = 3.7037 yd³
• Tons: 3.7037 × 1.4 = 5.19 tons, costing $233.33
• With 10% waste: 5.19 × 1.10 = 5.70 tons, costing $256.67

2. Construction entrance: 50 ft × 20 ft × 6 in, $45/ton, waste on

• Cubic yards: 50 × 20 × 0.5 ÷ 27 = 18.52 yd³
• Tons: 18.52 × 1.4 = 25.93 tons
• With 10% waste: 28.52 tons, about $1,283

At 28.52 tons this is usually two dump-truck loads. Confirm your hauler’s legal payload before booking delivery.

#2 stone compared with other clean stone

Stone	Approx. size	Tons per yd³ (typical)	Typical job
#1 stone	1½–3½ in	~1.4	Very heavy sub-base, rough fill
#2 stone	1½–2½ in	1.4	Construction entrances, base course, drainage beds
#3 stone	1–2 in	~1.4	Driveway base under a finer top layer
#57 stone	½–1 in	1.35	French drains, top layers, under sheds
Rip rap	6–24 in	1.5	Shorelines, ditch armor

Sizes are typical ASTM-style gradations; your local quarry may label stone differently, so compare by actual size rather than number alone.

Tons of #2 stone per 100 sq ft

Depth	Cubic yards per 100 sq ft	Tons per 100 sq ft
4 in	1.23	1.73
6 in	1.85	2.59
8 in	2.47	3.46
12 in	3.70	5.19

Figures are net, before the 10% waste allowance.

How to measure the area

• Length and width: measure the pad or bed in feet at ground level. For a construction entrance, measure from the paved road back into the site.
• Depth: use the full thickness of stone you plan to place. Clean #2 stone barely compacts, so loose depth and finished depth are almost the same.
• Odd shapes: split a flared entrance into a rectangle plus a triangle, or average the width at both ends.
• Soft ground: if tires sink when you walk the site, plan for geotextile fabric first. Stone dumped straight onto mud gets pressed into it and disappears.

Common mistakes with #2 stone

• Using it as the top layer. It stays loose. Cap a driveway base with crusher run or #57 stone.
• Entering depth in feet. The depth field is in inches. Typing 0.5 instead of 6 gives an answer 12 times too small.
• Ordering too short an entrance pad. A pad that ends before trucks have rolled a few tire rotations does not shed much mud. Check your local erosion-control spec for the minimum length.
• Ignoring the price per ton. Quarry prices for large stone vary widely. Enter your real quote so the cost line means something.

Related calculators

For finer drainage stone, use the #57 stone calculator or the drain rock calculator. For track beds and heavy foundations, the ballast calculator uses the same 1.4 tons per yard. For a mixed project, the gravel calculator handles circles and triangles too.