Stone Calculator for Drains, Bedding and Entrances Cut Before the Freeze

Trenching season here runs from the end of mud season to the first hard freeze, and it is shorter in the North Country than it is down on the Seacoast. That window, not the arithmetic, is what usually decides a stone order. Get the tonnage settled early, because a drain dug in October and stoned in November is a drain that works in April.

What the estimate cannot see once the bucket is in the ground

This stone calculator is honest about volume and says nothing at all about the hole you are actually going to dig.

Trench walls slough. A 12 inch trench in sandy outwash comes out at 15 or 16 by the time the stone goes in. In stiff till it holds its shape better. Either way, the figure you type is a plan, not a measurement of the finished cut.

Ledge moves the job sideways. Where granite surfaces mid-run, the trench gets shallower and longer, or it gets a different route. Probe before you order rather than after.

Water changes the depth you want. A drain that runs through ground still holding water in June wants more stone around the pipe than one cut into a dry terrace.

So order to the plan, then keep a small reserve. The last section of any trench is the one that swallows what was left.

2,800 pounds is the middle of the range, not the whole of it

Most graded stone on this site sits at about 2,800 lb per cubic yard, which is 1.40 tons. Several products do not.

Product	Per cubic yard	Tons per yard
#57, #67 and 3/4 inch crushed stone	about 2,800 lb	1.40
#89, #8 and 3/8 inch chips	about 2,800 lb	1.40
Stone screenings and dust	about 2,900 lb	1.45
#4 stone and railroad ballast	about 2,900 lb	1.45
Crusher run and road base	about 3,000 lb	1.50
Rip rap	about 3,100 lb	1.55

Cubic yards = area sq ft x depth in, divided by 12, divided by 27. Tons = cubic yards times the figure in the right-hand column.

Coverage, if you prefer to work backwards from square feet: a ton of ordinary crushed stone covers about 116 square feet at 2 inches, 77 at 3 inches, 58 at 4 inches and 39 at 6 inches.

Grades on a plan, and grades in the dropdown

Twelve graded options run through this page, from 3/8 inch chips up to 2.5 inch ballast. The numbers describe size ranges, and a lower number means bigger rock.

• #4 crushed stone, 3/4 to 1-1/2 inch. Heavy drainage, trench bottoms, construction entrances.
• #57 stone, 3/16 to 1 inch. The general-purpose drainage and concrete stone.
• #67 stone, 1/4 to 3/4 inch. Pipe bedding and tighter drainage.
• #8 crushed stone, 3/32 to 3/8 inch, and #89, 3/8 inch down to fines. Joints and finish layers.
• Railroad ballast, 1 to 2.5 inch angular. Wet ground under heavy load.

Local labels overlap the numbers. Around here, 3/4 clean and #57 usually mean the same rock, and stone dust is what everyone calls screenings.

One distinction worth holding on to: this page is for graded stone bought by its number or its size. The blended surfacing materials, where fines are part of the mix, belong on the gravel calculator.

Clean stone drains, stone with fines locks up

Two families, and putting one in the other's place causes real trouble.

Clean, washed stone such as #57 or drain rock stays open. Water moves through the gaps. That is what a French drain is.

Stone with fines, meaning crusher run or crushed gravel, compacts and binds. That is what a base is.

Fines in a drain plug it. Clean stone under a drive keeps shifting. Where a plan or a permit names a gradation, use the named material rather than the nearest thing on the shelf.

What the tool wants in each field

Shape first: rectangle for a pad or a trench, circle for a dry well or a ring, or multiple areas for up to five pieces added into one total.

Length, width and diameter in feet. For a trench, that is trench length by trench width. Depth in inches, anywhere from 0.25 to 24. Then the material, which is what the weight comes from.

Depth by what the layer is for: 2 to 3 inches on a top course, 4 inches on a base, 12 inches or more in a French drain.

The 5% box adds for compaction and spillage. Results come back as cubic yards, tons and cubic feet, and Email my quote sends them over in writing.

Forty-four feet of drain, and an entrance off a soft road

Both hypothetical.

A French drain along the uphill side of a camp. Forty-four feet, 18 inches wide, 18 inches deep, filled with #57.

• 44 x 1.5 = 66 sq ft
• 66 x 18, divided by 12 = 99 cu ft
• 99 / 27 = 3.67 cu yd
• 3.67 x 1.40 = 5.13 tons

Line the trench with non-woven fabric before the stone goes in, and do not bother subtracting the pipe. A 4 inch pipe displaces about 0.14 of a cubic yard over that run, which is a wheelbarrow.

A construction entrance where a camp road turns soft. Thirty-six feet by 11, 6 inches of #4 stone.

• 36 x 11 = 396 sq ft
• 396 x 0.5 ft = 198 cu ft
• 198 / 27 = 7.33 cu yd
• 7.33 x 1.45 = 10.63 tons

Bigger stone at that depth so loaded wheels shed mud before they reach the pavement.

Five to ten per cent, and the half ton you keep back

Angular clean stone settles 5 to 10 per cent once it has been rolled or driven on. The 5% box covers ordinary settling and spillage; engineered work follows its own specified compacted depth instead.

Round up. Coming back for half a ton means a second delivery for material that would have fitted in the corner of the first one.

Keep that reserve somewhere dry and out of the way. Trench tops sink over the first winter, and a wheelbarrow of the same stone in March is worth more than the tidy pile was in October.

When the figure looks right, open the product page, choose a quantity and a date, and delivery is arranged at checkout by ZIP code. The truck needs firm ground and clear room to tip. If the material name on your plan does not match anything in the dropdown, ask through contact before ordering, and the full set of calculators covers the rest of the job.

Common questions

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