Sand Calculator

What this sand calculator takes and returns

The calculator asks for three measurements and three order details. The measurements are the length and width of the area in feet and the depth of sand in inches. The order details are the sand condition, a waste allowance and the bag size you will buy. Press Calculate sand and the results table fills in the area, the volume in cubic feet and cubic yards, the weight in pounds and tons, the number of bags, how far one ton and one bag go at your depth, and the cost at your price per ton.

Sand comes in more grades than people expect, and each job has its own. Concrete sand is coarse and washed, masonry sand is fine and screens smooth, and play sand is washed and rounded for sandboxes. This page covers the quantity math that all of them share. If you are filling a children's sandbox with play sand at a set depth, the sandbox sand calculator walks through the depth standards in detail, and the polymeric sand calculator handles the sand swept into paver joints, which is priced by the pound of joint volume rather than by depth over an area.

Volume comes first: length x width x depth

Every sand order starts as a volume, and the volume is the footprint times the depth. Work in feet and inches, then divide the depth by 12 so the units match. For a 12 by 20 foot paver pad at 1 inch: 240 x 1 / 12 = 20 cubic feet, and 20 / 27 = 0.74 cubic yards. One cubic yard is 27 cubic feet, because a yard measures 3 feet on every side and 3 x 3 x 3 = 27.

Odd shapes do not need a surveyor. Split the area into rectangles, work each one out, and add the volumes. A circle uses 3.14 x r x r for the area, close enough that the waste margin absorbs the difference. L-shaped patios are two rectangles minus nothing, as long as the rectangles do not overlap.

Volume is the number to get right before weight enters the picture. Subgrades are rarely flat, so a pad specified at 1 inch deep has low spots that eat 2 inches and high spots that eat none. Sand also settles after rain and traffic. The waste allowance in the calculator exists for both reasons, and 10 percent is the default for a reason: it covers an uneven subgrade without doubling the order.

Dry, damp and compacted sand do not weigh the same

Volume tells you the hole. Weight tells you the truck, and the two are connected by density, which swings more for sand than for almost any other landscaping material. Dry, loose sand runs about 100 lb per cubic foot, which is 2,700 lb per cubic yard. Damp sand carries water between the grains and runs around 110 lb per cubic foot. Sand that is wet and compacted, the state it reaches under a plate compactor or after a week of rain, can reach 120 lb per cubic foot. The USGS tracks construction sand and gravel as a mineral commodity in its annual Mineral Commodity Summaries report, and material yards quote weights in the same dry-to-wet range.

What the condition does to a cubic yard:

Notice what this means in practice: the same 0.74 cubic yard hole holds anywhere from about 2,000 lb to 2,400 lb of sand depending on the day. If your supplier sells by the ton, the condition you pick changes the bill by about 20 percent. If the supplier sells by the yard, the condition changes the weight on your driveway, which matters when you are shoveling it or when a delivery truck parks on soft ground.

Tons, cubic yards and 50 lb bags

Suppliers sell sand three ways: by the cubic yard for bulk deliveries, by the ton at some yards and quarries, and by the 50 lb bag at retail. The conversions between them are fixed once you fix the density. With dry sand at 100 lb per cubic foot, one ton is 20 cubic feet, one cubic yard weighs 2,700 lb, and 2,700 / 50 = 54 fifty-pound bags per cubic yard.

Coverage is the same math read backwards. One ton of dry sand is 20 cubic feet, so spread over an area it reaches 20 x 12 = 240 square feet at 1 inch deep, and half that at 2 inches. Here is the coverage table for dry sand:

A single 50 lb bag holds about 0.5 cubic feet of dry sand, which covers 6 square feet at 1 inch or 3 square feet at 2 inches. That is enough to see why bagged sand suits patch jobs and mortar beds, and why anything over 20 bags is usually cheaper in bulk even after delivery fees.

Paver base: the 1 inch bedding layer

The most common sand order is the bedding layer under pavers. The stack is compacted gravel below, then a 1 inch layer of coarse concrete sand, screeded flat and never compacted, then the pavers themselves. The 1 inch figure matters in both directions: a thinner bed starves the low corners of the paver, and a thicker bed lets pavers sink under foot traffic, which is why installers screed with 1 inch pipes as rails and lay the pavers directly on the loose sand.

Work the bedding layer with the calculator by measuring the paved area and entering 1 inch of depth. A 12 by 20 foot patio, 240 square feet, takes 20 cubic feet or about 0.74 cubic yards before waste. The bedding sand is damp when it comes from the yard, so the calculator's 110 lb per cubic foot setting matches what the delivery weighs.

Two neighbors on this site cover the rest of the stack. The gravel calculator sizes the compacted base below the sand, and the polymeric sand calculator sizes the joint sand swept into the paver gaps afterwards. Bedding sand and joint sand are different products: bedding sand stays loose, while polymeric sand contains binders and sets after watering, so they are never interchangeable even though both are called sand.

Sandboxes, lawns and mortar beds

Depth is a design decision that changes with the job, and it is worth writing down before you measure:

A worked sandbox: a 5 by 5 foot box filled to 6 inches needs 5 x 5 x 0.5 = 12.5 cubic feet, which is 1,250 lb of dry sand or 25 fifty-pound bags. Play sand is the right grade here; construction sand can carry dust and sharp particles.

A worked mortar bed: 100 square feet of floor at 0.375 inch is 100 x 0.375 / 12 = 3.13 cubic feet. At 100 lb per cubic foot that is about 313 lb, or 6.25 bags, so buy 7. Mortar beds use masonry sand mixed with cement, roughly 1 part cement to 3 or 4 parts sand by volume.

What moves the number: moisture, waste and dust

Moisture is the first mover. Water fills the gaps between grains without adding volume, so a damp pile weighs 10 percent more than a dry one and a soaked pile up to 20 percent more, while covering exactly the same area. This is why sand is sold by volume at most yards: weight would charge you for last week's rain.

Waste is the second mover. Sand falls off shovels, sticks to wheelbarrows, disappears into low spots and spreads past the forms. The 10 percent default in the calculator matches what installers order for a reasonably flat pad; for sand going onto soft soil, or for a first job, 15 percent is more honest than 10.

Dust is the third thing to plan for, and it is a health question, not a tidy-up question. Sand and stone dust contain crystalline silica, and breathing the fine fraction causes silicosis. The OSHA silica standard for construction requires wet methods and dust controls when cutting or sweeping silica-bearing materials, and the rule itself sits in 29 CFR 1926 Subpart Z. Damp the pile before moving it and avoid dry sweeping the patio when the job is done.

A worked order, start to finish

Put the whole chain together for the 12 by 20 foot paver pad at 1 inch, buying damp sand with a 10 percent waste margin:

The last two rows are the argument for bulk. The same sand costs five times as much by the bag once you pass a couple of dozen bags, and that gap pays for a delivery fee several times over. Bags still win for small mortar beds, sandbox top-ups and jobs with no truck access. If the order needs other stone, the concrete calculator and the mulch calculator use the same area-times-depth starting point for their own materials.