Sand Calculator
Use this sand calculator to work out how much you need for a paver base, a sandbox or an aquarium, in cubic yards, tons and bags.
Area to Cover
Sandbox
Play sand is sold by the bag, so this panel leads with the bag count.
Aquarium Substrate
Measure the inside of the tank. Aquarium sand is sold by weight, so the answer is in pounds.
Sand Cost
How to use the Sand Calculator
Depth here depends entirely on the job. A leveling course under pavers is one inch, no more, because thicker bedding sand ruts under load. A sandbox wants four to six inches. An aquarium takes one to three inches depending on whether you are growing plants in it.
Bulk sand is sold by the cubic yard or the ton, bagged play sand by the pound, and aquarium sand by the pound again. The three tabs give the answer in whichever unit you are shopping in, from the same geometry.
Sand Cost prices whichever sand you picked, by the ton or the yard. Play sand and masonry sand are different products at different prices, so set the type before comparing quotes.
Sand formula
The volume is the same in every case:
volume = length × width × depthcubic yards = cubic feet ÷ 27
Weight and bag counts follow from a density:
pounds = cubic yards × lb per cubic yardtons = pounds ÷ 2,000bags = pounds ÷ bag weight, rounded up
| Sand type | Approx. lb per cubic yard | lb per cubic foot |
|---|---|---|
| Masonry sand | 2,700 | 100 |
| Concrete / coarse sand | 2,700 | 100 |
| Paver / leveling sand | 2,650 | 98 |
| Play sand | 2,550 | 94 |
| Fill sand | 2,800 | 104 |
Worked example
A 20 ft × 12 ft paver patio with a 1 inch leveling course, 5% waste:
- Area: 20 × 12 = 240 sq ft
- Volume: 240 × 0.0833 = 20 ft³
- Cubic yards: 20 ÷ 27 = 0.74, plus 5% = 0.78 yd³
- Weight: 0.78 × 2,650 = 2,061 lb = 1.03 tons
A 5 ft square sandbox filled 6 inches deep is 12.5 ft³, about 1,240 lb of play sand, or 25 bags at 50 lb each.
A 30 in × 12 in tank with 2 inches of substrate takes 0.42 ft³, about 42 lb of aquarium sand.
What the result means
The volume is exact. The weight is an estimate. Dry sand and wet sand from the same pile can differ by ten to fifteen percent, and a supplier delivering damp material is selling you some water along with the sand. Order by volume where the choice exists.
The aquarium figure has a built-in sanity check. At the density used here, one inch of substrate across a standard tank footprint comes out at roughly one pound per gallon of tank volume, which is exactly the rule of thumb the hobby has always used. A 20 gallon long tank with two inches of sand needs about 40 lb, and this calculator says 42.
Common mistakes
- Laying bedding sand too thick. One inch is the standard for a paver leveling course. Two or three inches feels safer and is the usual reason patios go wavy, the sand migrates under load.
- Using play sand as paver base. Play sand is fine and rounded, which is what makes it pleasant to sit in and useless as a load-bearing bedding layer. Paver sand is coarse and angular so it locks.
- Buying builder’s sand for a sandbox. Play sand is washed and screened for a reason. Masonry and fill sand carry dust and, depending on source, other things you would rather not hand a toddler.
- Measuring the outside of an aquarium. Glass and trim eat half an inch or more off each dimension. Measure the inside footprint.
- Ignoring the base under pavers. The one inch of sand sits on four to six inches of compacted gravel base. The sand is not the base.
Frequently asked questions
How much sand do I need for pavers?
One inch of leveling sand over the compacted base. For a 20 by 12 foot patio that is 20 cubic feet, or about 0.78 cubic yards with a 5 percent allowance, roughly one ton. Do not lay it thicker; bedding sand deeper than an inch shifts under traffic.
How many bags of sand do I need for a sandbox?
A 5 foot square sandbox filled 6 inches deep takes 12.5 cubic feet, which is about 25 bags of play sand at 50 lb each. Four inches deep drops it to about 17 bags.
How much does a cubic yard of sand weigh?
Around 2,500 to 2,800 lb dry, so roughly 1.3 to 1.4 tons. Wet sand runs noticeably heavier. Weights vary between pits, so use your supplier figure when you are buying by the ton.
How much sand does a 20 gallon aquarium need?
A standard 20 gallon long tank measures about 30 by 12 inches inside. Two inches of substrate is 0.42 cubic feet, or about 42 lb, which matches the familiar rule of one pound of sand per gallon per inch of depth.
How deep should aquarium sand be?
One inch is enough for a bare look and easy cleaning. Two inches suits most tanks. Three inches or more if you are growing rooted plants, though deep sand beds need stirring to avoid anaerobic pockets.
Is play sand the same as paver sand?
No. Play sand is washed, fine and rounded. Paver sand is coarse and angular so the grains interlock and hold pavers in place. Swapping one for the other gives you either a gritty sandbox or a patio that moves.
Sources and assumptions
Volume is exact geometry. Densities are mid-range dry values from landscape supply charts, which put sand at roughly 2,500 to 2,800 lb per cubic yard.
Moisture is the largest single source of error, wet sand can weigh ten to fifteen percent more than the same sand dry, so tonnage and bag counts are estimates and volume is the figure to order on.
The aquarium calculation uses 100 lb per cubic foot, which reproduces the hobby’s long-standing one-pound-per-gallon-per-inch rule to within a few percent.