Sand Calculator — California

Sand is not one product. The yard stocks several sands, each screened and washed for a different job, and the wrong one fails even when the tonnage is right. Pick the sand by the task first, then size the order with this calculator. The amount comes from your area and depth, but the grade comes from what the sand has to do.

Concrete sand, also called sharp sand or ASTM C33 sand, is a coarse, angular sand screened for mixing concrete. Its grains are gritty and run across a range of sizes, which is what lets a concrete or mortar mix grip. The same traits make it the common choice for a paver bedding course and for filling the joints between pavers, where it locks in place instead of washing out.

Mason sand is a finer, more even sand, washed and screened smooth for mortar and plaster. Masons use it where a coarse grit would show in a thin joint. It also serves as a clean play sand and a soft fill. Because it is finer than concrete sand, it packs tight and holds water longer, so it makes a poor bedding sand under pavers.

Fill sand is the cheap, unwashed sand you buy in bulk to raise grade, backfill a trench, or build up a low area. It carries more silt and fine material than a washed sand, so it is not for a finished surface or a concrete mix. Play sand sits at the other end: a fine sand that is washed, screened, and often sifted again so it is clean and safe for a sandbox.

Ask your supplier for the sand by name, not just sand, because a yard may stock four or five grades at different prices. Confirm whether it is washed or unwashed, coarse or fine, before you load. The calculator sizes the volume the same way for any grade, so once you know the right sand, the area and depth give you the tons to order.

Grain shape matters as much as grain size with sand. Sharp sand has angular grains with broken, gritty faces. Rounded sand has smooth grains worn round by water. The two behave in opposite ways under load, so the shape, not just the label, decides where each one works.

Angular grains catch and wedge against each other. That interlock is why sharp concrete sand grips in a mortar mix and why it stays put in a paver joint and in a bedding course. Press on a sharp-sand bed and the grains lock rather than roll, so a paver set on it holds its line.

Rounded grains roll past one another easily. A rounded sand flows and levels with little effort, which suits some fills, but it will not lock. Under pavers it keeps shifting, so the joints open and the surface ruts. This is why a smooth, rounded play or fill sand is the wrong bedding sand even though it spreads nicely.

The grip that makes sharp sand good for bedding still does not set it into a hard layer. Sand has no range of fine particles to bind it the way a dense-graded base does, so even angular sand stays a loose, workable course. That is the point of a bedding sand: it supports the paver yet stays free enough to let you set each one true.

Match the shape to the task. Reach for angular, sharp concrete sand under and between pavers and in any mix. Use a finer or rounded sand only where you want an easy, loose fill that carries no real load. The calculator does not change with grain shape, but your choice of sand should.

Sand does something crushed stone does not: it bulks when it is damp. A film of water around each grain pushes the grains apart, so moist sand takes up more space than the same sand dry or tight. A loose cubic yard of damp sand holds fewer grains than a cubic yard of dry, settled sand. This is the one estimating trap that is special to sand.

Bulking means the volume you see on the truck is not the volume you end up with on the ground. Damp sand delivered loose looks like plenty, then shrinks as it dries and as you tamp it into place. The placed, settled layer is smaller than the loose pile, so an order sized to the loose pile falls short.

This calculator handles the gap with an overage allowance, set to 10 percent by default. It sizes the volume from your area and depth, then adds that overage so the sand you buy still reaches your depth after it settles and after normal spillage. Keep the overage on. Raise it on a rough site or a deep fill, where more sand disappears into low spots and settling.

Moisture also changes the weight, which is a separate effect. Wet sand weighs more per cubic yard than dry sand, because water fills the gaps. The space you must fill does not change, so your cubic-yard figure holds, but the delivered tonnage on the supplier's scale can read higher when the sand is soaked. Do not confuse this weight swing with the volume bulking.

The practical rule is to order to your finished, settled depth and trust the overage to cover the bulk and the shrink. Sand that arrives damp is normal and often easier to spread without blowing around. Just remember the loose pile will settle, so measure your success by the depth after tamping, not by how high the fresh pile looked.

A paver bedding course is thin on purpose. You want just enough sand to set each paver true and no more. A common bedding layer is about one inch, which is the leveling preset in this calculator. Enter one inch for a paver leveling course and the tool sizes the sand for that thin layer.

Set the depth with two screed rails. Lay straight rails or pipes at your target thickness, fill between them with sharp sand, then drag a straight board across the rails to strike the sand flat. Pull the rails and fill the grooves they leave. This gives a flat, even course, which is what pavers need to sit level and share the load.

Resist the urge to lay a thick bed. Over-sanding is a common paver failure: a deep sand layer is soft and mobile, so the pavers settle unevenly, rock, and rut under traffic. A thick bed does not fix a rough base. It hides the rough base, then moves. Fix the grade in the compacted base below and keep the sand itself thin.

Screed the sand, set the pavers, and avoid walking on the struck bed before you lay them. A footprint in a screeded course is a low spot that shows up as a dip later. Work off the pavers you have already set, not off the loose sand. Then sweep a jointing sand into the gaps once the field is down.

Measure the finished depth after you have set and tamped the pavers, not off the loose sand. A bedding course beds in a little as the pavers settle, so the struck one inch is not the final one inch. The calculator gives you the sand for the placed layer, and the overage covers the small loss as it beds.

Sand and a crushed-stone base can look alike in a pile but behave in opposite ways. A dense-graded base carries a full range of sizes, from stone down to fines, so it packs into a hard, locked layer. Sand is a narrow range of loose grains with no fines to bind it, so it never sets that way. Knowing this keeps you from using sand where a base belongs.

Because the grains are loose and open, water runs through sand quickly. That free drainage is useful. A thin sand course lets water pass instead of trapping it under a paver, and sand around a buried pipe cushions it and drains. But the same openness means sand carries no structural strength on its own.

Sand also does not compact into a firm platform the way a base does. You can tamp a bedding course so it stops moving, but it stays a loose, workable layer by design. Try to build the whole depth of a driveway or a patio out of sand and it shifts and ruts under load. Sand is the thin setting layer, not the structure.

This is why a paver section is built in two parts. A compacted crushed-stone base takes the load and holds the shape. A thin sand course on top lets you level each paver. Size the base with the paver-base or gravel calculator and size only the thin bedding sand here, then add them for the full dig depth.

Use sand for what it does well: drainage, cushioning, and a true setting bed. Use a dense-graded base for load and shape. If a job needs a thick layer that has to carry weight, that layer is base, not sand, however tempting the cheaper fill sand looks.

Once you know which sand you need, the numbers are quick. Enter the area as a length and width, or type a square-foot area for an odd shape, and set the depth in inches. The calculator turns inches to feet, multiplies by the area for cubic feet, divides by 27 for cubic yards, and multiplies by the sand density for a weight in tons.

It reports both cubic yards and tons because suppliers use both. Cubic yards measure the space you are filling. Tons measure the weight the pit loads and the truck carries. Common bulk sand runs about 1.35 tons per cubic yard, in a range near 1.3 to 1.4, so one cubic yard weighs a little over a ton. Check the figure the tool gives against your supplier's quote, and confirm which unit they bill.

Match the depth to the job before you read the tons, because depth moves the total more than anything else. A paver leveling course is about one inch. A base fill often runs two inches or more. A sandbox is filled six to ten inches deep. Pipe bedding follows the trench detail. Measure an uneven depth at several points and enter the average.

Bulk sand arrives loose by dump truck, and one truck holds roughly 10 to 14 tons. Divide your tons by that range to see the loads. A small bedding job may fit a few bagged sacks instead, which cost more per ton but suit a sandbox or a single course. A large fill may take a full truck or more, so order in full loads where you can.

Plan the drop before the truck comes. The driver needs firm ground, room to raise the bed, and clear space overhead. Mark a dump spot clear of gates, drains, and parked cars, and lay a tarp under the pile to keep the sand off a lawn or a drive. Spread loose sand soon after it lands, while it is still easy to move.

Most short or failed sand orders trace to a few repeatable errors, and each is easy to avoid. The first is buying the wrong sand for the job. A fine mason or play sand under pavers washes out and shifts, while a dirty fill sand ruins a concrete mix. Pick the grade by the task before you size the tons.

The second is laying the bedding course too thick. A deep sand bed is soft and mobile, so pavers settle and rock. Keep the bedding near one inch, screed it flat, and build any real depth into the compacted base below, not into the sand.

The third is forgetting that damp sand bulks and then settles. Order to the loose pile and the layer comes up thin once it dries and you tamp it. Keep the overage allowance on, and measure the finished depth after settling, not off the fresh pile.

The fourth is mixing units: ordering cubic yards when the pit sells by the ton, or the reverse. The two are not interchangeable, so confirm the supplier's unit and use the matching figure from the calculator. The fifth is treating a thick sand layer as a load-bearing base. Sand drains and cushions, but it does not lock, so a structural layer has to be a crushed-stone base instead.

The last is measuring an irregular area as one rectangle. Curves and cutouts throw off the square footage, which throws off the tons. Split the site into simple rectangles, size each in the calculator, add the results, then round the order up so a little margin covers the uneven ground.