Key Takeaways
- Sand is bought by weight, but the amount you need starts as a volume
- Volume is length times width times depth, with depth converted to feet
- A density figure turns that volume into pounds, then tons
- Density varies with grain size and moisture, so a supplier figure beats a default
- A waste allowance covers spillage and an uneven base before bagging or delivery
Sand for a paver base, a playground, or bedding under a slab is sold by weight, at the ton or in bags, but nobody measures a project in pounds before they start digging. The starting point is always a volume, and getting from that volume to an order quantity takes one more number: how much a cubic foot of that particular sand weighs.
Volume first
Multiply length by width to get the area in square feet, then multiply by the depth in feet. Depth is usually specified in inches, so divide it by 12 first. A 10 by 10 foot area at 2 inches deep covers 100 square feet and needs 100 x (2/12) = 16.7 cubic feet.
Volume to weight, with a disclosed assumption
Cubic feet is not how sand gets priced or delivered. To convert to weight, multiply the volume by a density figure in pounds per cubic foot. A common working figure is around 100 lb per cubic foot, but this is exactly that, a working figure, not a physical constant. Sand density shifts with grain size, how it was screened, and how much moisture it is carrying when it is weighed at the yard. Wet sand from a supplier’s outdoor stockpile after rain will weigh more per cubic foot than the same sand dry. If your supplier can give you a density or a weight-per-yard number for the actual product you are buying, use theirs over any general default.
Waste, bags and tons
A waste allowance, commonly around 10 percent, is added to the raw weight before finalizing an order. It covers spillage during handling and a subgrade that is never perfectly flat, both of which eat into material without adding to the area actually covered. For bagged sand, the total weight needed is divided by the bag size and rounded up, since a partial bag still has to be bought whole. For bulk delivery, the total is usually expressed in tons, since that is how most yards price and haul sand.
Run your own length, width and depth through the sand calculator to get the volume, weight in tons, and a bag count if you are buying bagged sand. If the project also needs a compacted base layer under the sand, such as crushed stone under paver bedding sand, the aggregate calculator handles that step separately, since aggregate is ordered as a loose volume that accounts for how much the material settles once it is compacted.