Frequently asked questions

Multiply the area by the depth to get a volume, then multiply the volume by the material's density to get a weight. A 20 by 10 foot area at 4 inches deep is 200 square feet, which works out to 66.7 cubic feet or 2.47 cubic yards. In #57 stone at a typical 1.4 tons per cubic yard, that is about 3.46 tons, or roughly 3.8 tons once a ten percent allowance is added. The calculator on this page does all of that and shows each step.

Between about 1.25 and 1.5 tons for most gravels, with 1.4 tons per cubic yard being the figure quoted most often for washed stone such as #57. It is not a fixed conversion: it depends entirely on the density of the specific material. Crusher run runs heavier, at around 1.5 tons per cubic yard, because the fines fill the gaps between the stones. Lava rock is far lighter, at roughly 0.55. Your supplier can tell you the figure for the pile you are actually buying, and the calculator lets you enter it.

It depends on what the surface has to carry, and no single number covers every job. Decorative beds and paths are commonly laid 2 to 3 inches deep. A gravel driveway is usually built much deeper and in layers, often 4 to 8 inches in total. A paver base commonly runs 4 to 6 inches of compacted base before any bedding sand. These are common starting points rather than requirements: soil type, drainage, climate, the load involved and local practice all change what a specific job needs, and anything structural should follow whatever your local building department requires.

Forty 50 pound bags make up a US short ton, because a short ton is 2000 pounds. That part is exact arithmetic and does not depend on the material. Bags sold by volume are different: a 0.5 cubic foot bag of a heavy crushed stone holds more weight than the same bag of lava rock, so the number of bags per ton changes with density. The calculator handles both, converting a volume labelled bag through the density you selected.

Usually yes, and ten percent is the allowance most people settle on. It covers spillage during delivery and spreading, ground that is not as level as it measured, cuts and edges, and the fact that loose gravel settles once it is compacted. For a large driveway or a job with awkward edges, fifteen percent is not unreasonable. The important thing is that the allowance is visible rather than baked in, which is why the calculator shows the bare requirement, the allowance and the final order quantity as three separate numbers.

In bulk it almost always is, once you get past a small quantity, but delivery is what decides it. Bulk material has a low price per ton and a delivery fee that does not change much with quantity, while bags have a high price per unit and often no delivery charge at all. So there is a crossover point, and where it falls depends on the two quotes in front of you. The calculator compares them directly: enter your bulk price, your delivery fee and your bag price, and it works out which is cheaper for your actual quantity.

It depends on the truck and on what the local axle weight limits allow, so treat any single figure with caution. A pickup might carry a ton, a single axle dump truck several tons, and a tandem axle truck considerably more. The limit is often the legal weight rather than the space in the body, which is why the same truck carries fewer cubic yards of a dense crushed stone than of a light decorative rock. Ask your supplier what their trucks carry and enter that number, rather than relying on a general figure.

Yes. Choose the irregular option and split the space into rectangles, entering each one as its own section. The calculator adds them up and shows both the area of each section and the total, which is also a quick way to check you have not measured the same strip twice. For curved or genuinely awkward shapes, the circle, ring, triangle and trapezoid options cover most of what turns up, and you can always measure the area yourself and enter it directly.

Measure the area you are covering in feet or metres, decide on a depth, then run those two numbers through the calculator along with the material you are using. It converts the area and depth into a volume, the volume into a weight using the material's density, and adds a waste allowance to give you an order quantity. Doing it by hand is the same three steps: area times depth in feet gives cubic feet, divide by 27 for cubic yards, then multiply by tons per cubic yard for weight. Density is the only value that changes with material, which is why it is always editable.

At a typical 1.4 tons per cubic yard, one ton of gravel covers roughly 116 square feet at a 2 inch depth, 77 square feet at 3 inches, or 58 square feet at 4 inches. The deeper the layer, the less ground the same ton covers. Because that figure depends entirely on density, a lighter decorative stone spreads further than a dense crushed stone at the same weight and depth. Enter your own material and depth in the reverse coverage calculator for the exact figure rather than the typical one.

A 10 by 10 foot area is 100 square feet. At a common 4 inch depth, that is 33.3 cubic feet, or about 1.23 cubic yards. In #57 stone at a typical 1.4 tons per cubic yard, the bare requirement is roughly 1.73 tons, or about 1.9 tons once a ten percent allowance is added. A shallower 2 inch decorative layer needs roughly half that. Enter your own depth and material above for the exact figure: both change the answer more than the 10 by 10 footprint does.

Roughly 1.5 to 1.8 metric tonnes for most crushed stone and gravel, with about 1.6 to 1.7 tonnes per cubic metre typical for washed stone such as #57. That range comes directly from converting the same 1.3 to 1.5 short tons per cubic yard this site uses, through the exact 0.7646 cubic metres in a cubic yard. As with every density figure here, it is a published planning value, not a measurement of the specific pile you are buying, so a supplier's own figure for their material is more reliable than any general range.

No. A ton is a unit of weight and a cubic metre is a unit of volume, and the two only relate to each other through density, which is different for every material. A cubic metre of gravel weighs roughly 1.5 to 1.8 tonnes depending on what it is, while a cubic metre of water weighs almost exactly one tonne, which is usually where the confusion comes from. Converting between weight and volume for gravel always goes through that material's density, the same calculation the calculator performs automatically once a material or a custom density is entered.

In terms of what it does rather than what it costs, since prices vary too much by region and supplier for a figure here to be reliable: a tonne of typical crushed stone is roughly 0.6 cubic metres, enough to cover about 12 square metres at a 5 centimetre depth or 6 square metres at 10 centimetres. For an actual cost, enter your own supplier's price per tonne into the cost section of the calculator; it works out the total for your quantity, delivery included, rather than guessing at a national average that would not match your area.

Forty bags at the common 50 pound size, since a US short ton is exactly 2000 pounds. That count only holds for bags sold by weight; a bag sold by volume, such as a 0.5 cubic foot bag, holds a different weight depending on the material's density, so a heavy crushed stone weighs more per bag than a light decorative one at the same volume. The bags panel in the calculator works out the exact count for whichever bag size and material is selected, rather than assuming the 50 pound, 40 bag figure applies to every product.

About 1.2 cubic metres of typical crushed stone. Spread out, that covers roughly 24 square metres at a thin 5 centimetre decorative depth, or 12 square metres at a firmer 10 centimetre depth, using the same conversion the calculator runs automatically. The exact volume depends on the material's density: a lighter stone such as lava rock takes up noticeably more space than a dense crushed stone at the same 2 tonnes, because it takes more of it to reach the same weight.

Roughly 1,500 to 1,800 kilograms for most crushed stone and gravel, with about 1,600 to 1,700 kilograms typical for washed stone such as #57. That is the same range as the tonnes per cubic metre answer above, just in kilograms: multiply tonnes per cubic metre by 1,000. Lighter decorative materials such as lava rock weigh considerably less, around 500 to 700 kilograms per cubic metre, which is why the calculator's density field always names the specific material's range rather than one number that would be wrong for many products.