Pea Gravel Calculator for Patios, Paths and Play Areas
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Pea gravel and crushed walkway gravel look interchangeable in a photograph and behave nothing alike on the ground. Rounded 3/8 inch stone is comfortable underfoot and will not lock together, which is why it sits beautifully in a level fire-pit surround and creeps steadily downhill on a Blue Ridge slope. This pea gravel calculator converts an area into tons, and the errors below are the ones that make a correct tonnage into the wrong order.
Ordering rounded stone for a job that needs angular stone
The stones will not interlock, so anything on a grade of about 5 per cent or more, or on a route people use daily, is better in walkway gravel, which grips itself and stays put. Rounded stone belongs on level ground: seating areas, fire-pit surrounds, dog runs and play zones. On a long path that starts level and climbs, using both materials by section is entirely reasonable.
Entering 4 inches because deeper sounds harder wearing
Two to three inches is the range for anything walked on. Below 2 inches the ground shows through within a season; above 3 inches feet sink as they would in dry sand, and chairs go with them. Entering 4 inches buys a third more stone and a worse surface, and the depth (inches) field will accept it without comment, since it takes anything from 0.25 to 24.
Using a patio depth under play equipment
A fall zone is a different specification. Loose fill under equipment is maintained at 9 to 12 inches, which is four times a patio depth, and the equipment manual sets the figure. At 12 inches a ton of pea gravel reaches only about 19 square feet, so a play area is a bulk order rather than a bag job. Work it out rather than eyeing it. And note what the tonnage buys: landscape pea gravel, not certified playground surfacing. The required depth, the fall-zone footprint and the maintained depth all come from the equipment manufacturer's instructions rather than from us.
Calculating the quantity and then leaving it unbordered
The tonnage can be exactly right and half of it still ends up in the lawn. Rounded stone migrates wherever the border sits flush or has dropped, so set steel, aluminum, timber or paver edging an inch above the finished surface. On a grade steeper than about 5 per cent, add a honeycomb stabilizing grid under the gravel or change material.
A 20-foot seating circle in the Roanoke Valley
An illustrative job. A circle 20 ft across is measured by its diameter, so switch the shape row to circle and enter 20. Half of 20 is 10, and 10 x 10 x 3.14 gives about 314 square feet.
At 3 inches, which is a quarter of a foot, 314 x 0.25 is 78.5 cubic feet. Divide by 27 for 2.91 cubic yards. Pea gravel is published here at about 2,800 lb a cubic yard, which is 1.4 tons, so 2.91 x 1.4 comes to 4.07 tons. That is the figure that surprises people: it feels soft to walk on and weighs the same as crushed gravel.
Underneath it goes 2 inches of compacted screenings so chair legs have something to bear on. Over the same 314 square feet that is 52.3 cubic feet, or 1.94 cubic yards, and screenings run a little heavier at about 2,900 lb a yard, so about 2.8 tons. Two materials, two calculations, one delivery.
Where each figure on the panel is useful
Cubic yards answer whether the pile will fit the corner of the drive you have set aside. Tons is the ordering unit. Cubic feet is the one to keep for later, when a traffic track has thinned and you want to know what a bucket or two will cover.
Coverage falls out of the same arithmetic: a ton spread 2 inches deep covers about 116 square feet, at 3 inches about 77, and at 4 inches about 58. If you want a quick sanity check on any result, divide the square footage by those figures and see whether the tonnage lands in the same place.
Rectangle takes length and width in feet, circle takes a diameter, and multiple areas holds up to five entries, which is how a seating circle and the path leading to it get totaled in one go. The material select fixes the weight conversion, the optional tick box, ticked by default, adds 5 per cent for compaction and spillage, and Email my quote sends the result to you.
Choosing between three rounded and angular options
Pea Gravel is screened to roughly 3/8 inch with mixed river coloring, and it is the comfortable one underfoot. River Rock is larger and decorative, meant for beds, borders and dry creek beds rather than walking surfaces, and it is lighter per yard at about 2,700 lb, so it is worth taking a minute to compare a river rock bed on the same footprint. Crushed walkway gravel is the angular option that binds on a slope.
For pipe bedding or paver joints, small washed stone such as #8 stone does that work instead. Every one of them is calculated the same way here, so it costs a minute to compare tonnages over the same footprint.
Depths by job, and what Virginia weather does to them
Fire-pit surrounds take 3 inches; the stone will not burn and rain drains out of the seating area overnight, which matters through a thunderstorm summer. Dog runs take 2 to 3 inches, easy on paws and simple to rinse. Paths take 2 to 3 inches over a compacted base, and you size the base course as its own calculation. A play area at 17 ft by 12 ft held at 10 inches works out at 204 square feet x 10/12, or 170 cubic feet, which is 6.3 cubic yards and about 8.8 tons.
Rake the surface level twice a year and top the worn track every couple of seasons. When the numbers look right, set quantity and date on the product page and check the drop point by ZIP at checkout.
Common questions
Do I need a separate calculation for the layer underneath?
For anything with furniture on it, yes. Run the 2-inch screenings base as its own entry at its own weight, then the pea gravel over it at 2 to 3 inches. A dog run or a play area can go straight onto stripped, firm ground, so there the surface figure is the whole order.
The path curves around the fire pit and has no straight edges. What do I measure?
Walk the center line with a tape for the length, measure the width at three points and average it, then enter it as a rectangle. A curved path is close enough to a long strip for a stone order, and the curve tends to eat about as much as the corners give back.
The surface has thinned down the middle. How much do I enter to bring it back?
Measure how far the worn strip has dropped below the edges rather than the full surface depth. A track that has gone down an inch over a 3 ft by 20 ft run is 60 square feet at 1 inch, about 0.19 of a yard, so a quarter ton finishes it. The depth field goes to a quarter of an inch, so thin repairs are still worth calculating.
What if the load is a quarter ton light?
The surface finishes thin and the base shows through in the walked line first. Rounded stone spreads and settles into whatever is beneath it in the first few weeks, so a modest surplus kept under a tarp is the sensible insurance rather than a second small delivery.
How close does the estimate come on rounded stone?
The volume arithmetic is exact, and the weight is the published figure for this material. What moves in practice is settlement into the base and the stone that escapes past a flush border. Where the edging sits proud and the base is compacted, the result is usually within a wheelbarrow load or two of what you place.
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