#57 Stone Calculator

How much #57 stone do I need?

This #57 stone calculator multiplies length × width × depth to get cubic feet, divides by 27 to get cubic yards, and multiplies by 1.35 tons per cubic yard to get the tons you order. Quarries sell #57 by the ton, so the result is in tons, and the cost line is tons × your price per ton. Tick the waste box to add 10% to the order.

#57 is clean, angular stone about the size of a grape or a little larger. Because the fines have been washed out, water passes straight through it. That makes it the usual choice for French drains, pipe bedding, and driveway top layers.

The #57 stone formula in plain words

1. Convert depth to feet: inches ÷ 12. Four inches is 0.333 ft.
2. Find cubic feet: length × width × depth in feet.
3. Convert to cubic yards: cubic feet ÷ 27, since a cubic yard is 3 × 3 × 3 ft.
4. Convert to tons: cubic yards × 1.35.
5. If the waste box is ticked, multiply tons by 1.10.
6. Cost = tons × price per ton.

The 1.35 figure is lighter than the 1.4 to 1.5 used for crusher run or road base. Without fines, more of every cubic yard is air.

Worked examples

The calculator gives the same results.

1. Driveway top layer: 20 ft × 10 ft at 4 in, $50 per ton

• Cubic feet: 20 × 10 × 0.333 = 66.7 ft³
• Cubic yards: 66.7 ÷ 27 = 2.47 yd³
• Tons: 2.47 × 1.35 = 3.33 tons, or $166.67
• With the 10% box ticked: 3.67 tons, $183.33

2. French drain trench: 50 ft long × 1.5 ft wide × 12 in of stone, $50 per ton

• Cubic feet: 50 × 1.5 × 1 = 75 ft³
• Cubic yards: 75 ÷ 27 = 2.78 yd³
• Tons: 2.78 × 1.35 = 3.75 tons, or $187.50
• With 10% extra: 4.13 tons, $206.25

For a trench, enter the trench length as length, its width as width, and the stone depth as depth. The perforated pipe takes up a little room, but most installers ignore that and let it become part of the margin. The French drain gravel calculator handles trench fill in more detail.

#57 stone coverage per ton

Depth	Area one ton covers	Tons per 100 sq ft
2 in	~120 sq ft	0.83
3 in	~80 sq ft	1.25
4 in	~60 sq ft	1.67
6 in	~40 sq ft	2.50
12 in	~20 sq ft	5.00

These numbers are net, before the 10% allowance.

Where #57 stone works, and where it doesn’t

Use	Typical depth	Why #57 suits it
French drain / curtain drain	Full trench, 2 in under pipe	Open voids carry water to the pipe
Driveway top layer	2–4 in	Clean look, sheds water, less mud than fines
Under a shed or deck	4 in	Drains and stops splash-back
Behind a retaining wall	12 in wide drainage zone	Relieves water pressure on the blocks
Concrete aggregate	—	It is the standard coarse aggregate in many mixes
Paver base	Not ideal	Won’t compact flat; use crusher run instead

How to measure

• Measure only the #57 layer. If the stone sits on a separate compacted base, enter just the depth of the top layer, not the whole driveway.
• Use the excavated size. For drains and footings, measure the trench as dug, which is usually wider than planned.
• Break up odd shapes. Split an L-shaped pad into two rectangles, run each, and add the tons.
• Average the depth. On sloped ground, take depth readings at three or four spots and enter the average.

Common mistakes with #57 stone

• Using it as the only base for pavers or a slab. Rounded voids let it shift under load. Put crusher run underneath where you need a hard, flat base.
• Ordering by the yard but reading tons. If your supplier sells by the cubic yard, divide the tons result by 1.35, or use the general gravel calculator, which shows both units.
• Skipping fabric in drains. Wrap the trench in non-woven filter fabric so soil does not wash into the stone and clog it over time.
• Confusing #57 with #67 or #8. #67 is a slightly smaller mix and #8 is pea-sized. Check the number on the quote before the truck arrives.

For mixed loads or other aggregate sizes, see the crushed stone calculator.