Sand Calculator
Estimate how much sand you need for a sandbox, paver base, or pool floor. Enter the area dimensions, sand depth, and sand type to get the volume, weight in tons or tonnes, bag count, and cost.
Estimate Sand Needed for a Project
Sand Formula
Where:
- \(V\) — volume of sand needed
- \(A\) — area to be covered (length \(\times\) width for a rectangle, or \(\pi d^2/4\) for a circle)
- \(d\) — sand depth
- \(W\) — weight of the sand
- \(\rho\) — bulk density of the sand (about 100 lb/ft³ dry, 120 lb/ft³ wet)
- \(w\) — waste allowance in percent
The first formula gives the volume, the second converts volume to weight using the sand's density, and the third adds a waste factor to the amount you should actually order.
Sand – Calculation Example
Example: you are putting a 2-inch layer of dry sand under an above-ground pool in a rectangular area 12 ft long and 10 ft wide, with a 5% waste allowance.
\[ A = 12 \times 10 = 120 \text{ sq ft} \]
\[ V = 120 \times \frac{2}{12} = 20 \text{ ft}^3 \approx 0.741 \text{ yd}^3 \]
\[ W = 20 \times 100 = 2000 \text{ lb} \]
\[ V_{order} = 20 \times 1.05 = 21 \text{ ft}^3, \quad W_{order} = \frac{2000 \times 1.05}{2000} = 1.05 \text{ US tons} \]
Result: you need 20 ft³ (0.741 yd³) of sand and should order about 21 ft³ ≈ 0.78 yd³, which is 1.05 US tons (0.95 metric tonnes) or 42 fifty-pound bags.
How to Use the Sand Calculator
- Choose the Area shape: rectangle, circle, or enter a known total area directly.
- Enter the Length and Width (for a rectangle), the Diameter (for a circle), or the Total area — only the fields for your chosen shape are shown. Pick the matching units.
- Enter the Sand depth in inches or centimeters. Typical depths: about 1 in for a paver base, 12 in for a sandbox, 2 in under a pool.
- Select the Sand type, which sets the density. Choose Custom density if you know the actual value in lb/ft³ and enter it in the field that appears.
- Set the Waste allowance — this is added to the order, not the calculated volume.
- Optionally enter a Price per US ton, metric tonne, or 50 lb bag to get a cost estimate. Clear this field to omit it.
- Read the results: volume in ft³, yd³ and m³, the amount to order including waste, weight in US tons and metric tonnes, the number of 50 lb and 0.5 ft³ bags, and the estimated cost.
What the Sand Calculator Does
The calculator converts your measurements into a total volume, then into a weight. Volume is what determines delivery size — sand is commonly sold by the cubic yard — while weight matters when it is sold by the ton or in bags. Because different sands have different densities, the result also gives you the weight using the density of the sand type you selected.
Density makes a real difference. Dry loose sand weighs about 100 lb/ft³, but wet sand is roughly 20% heavier at about 120 lb/ft³. Masonry sand is slightly denser at about 105 lb/ft³. If your sand's density is printed on the bag or quoted by the supplier, use the custom density option for the most accurate weight and tonnage.
The waste allowance covers spillage, uneven ground, sand lost during spreading, and small measurement errors. A 5–10% allowance is typical for simple jobs; for compacted paver bases, where sand settles and you need extra material, 10–15% is safer. Note that compacted sand occupies less volume than loose sand, so a calculator based on loose density tends to underestimate what a compacted base will need.
The two bag counts serve different purposes. The 50 lb bag figure is based on weight and suits bulk sand products. The 0.5 ft³ bag figure is based on volume and matches the small bags of play sand sold for sandboxes. Both are always rounded up, since you cannot buy a fraction of a bag.
Tips and Limitations
- Buy by volume when possible. Suppliers usually quote bulk sand per cubic yard; the calculator gives both the volume and the tonnage so you can compare quotes.
- Compaction is not included. If the sand will be compacted (for example, under pavers), the same loose volume will settle, so order more than the calculator suggests for such projects.
- Densities are typical values. Actual bulk density varies with grain size and moisture. If precision matters, ask your supplier for the material's density and enter it as a custom value.
- Odd shapes: for an L-shaped area, split it into rectangles, calculate each separately, and add the volumes — or measure the total area and use the "Total area (known)" option. If you need help measuring, a square footage calculator can be useful.
- Related materials: for other ground-covering materials, see the topsoil calculator and the asphalt calculator.
- Delivery matters. Small orders in bags cost far more per unit than bulk delivery; above roughly one cubic yard, delivered bulk sand is usually cheaper.
Frequently Asked Questions
How do I calculate sand by hand without the calculator?
Multiply the area by the depth, making sure the depth is in the same unit as the area. For feet: \( V = A \times d \). For example, 100 sq ft filled 3 inches (0.25 ft) deep needs \( 100 \times 0.25 = 25 \) ft³. To convert, divide ft³ by 27 to get cubic yards, or multiply by 0.02832 to get cubic meters. To get weight, multiply the volume by the sand's density in lb/ft³.
How many cubic yards are in a ton of sand?
A US ton is 2000 lb. Dry loose sand at roughly 100 lb/ft³ means one ton occupies about 20 ft³, which is \( 20 \div 27 \approx 0.74 \) cubic yards. Wet sand at 120 lb/ft³ is denser, so a ton only fills about 0.62 yd³. Because moisture changes the density noticeably, always confirm with your supplier whether their price is per ton or per yard.
How much sand do I need for a standard sandbox?
A common 5 ft × 5 ft sandbox filled 12 inches deep needs \( 25 \times 1 = 25 \) ft³, which is roughly 50 of the 0.5 ft³ bags of play sand, or about 1,250 lb. Many parents fill to only 6–8 inches so the sand stays below the rim; that reduces the need to 12–17 ft³. Add 5–10% extra for settling and spillover.
How deep should the sand layer be for pavers or an above-ground pool?
For a paver base, a sand setting bed of about 1 inch is typical, spread over compacted gravel. Under an above-ground pool floor, 2 inches is the usual recommendation to cushion the liner and hide small imperfections. Going much deeper under pavers can cause sinking, while an overly thick pool base shifts when sand washes out from under the liner.
Does wet sand weigh more than dry sand, and will I get less volume per ton?
Yes. Wet sand weighs around 120 lb/ft³ versus about 100 lb/ft³ dry, so a delivered wet ton takes up roughly 20% less volume than a dry ton. You still get the correct weight, but if your project is measured in volume (cubic yards), wet sand means fewer yards per ton. Pick the wet sand option in the calculator or ask the supplier for the delivered moisture content.
Why does my paver base seem short even though the math was right?
The calculator uses loose (uncompacted) density, but paver sand is compacted in lifts, so it settles into less space. A common practice is to order about 10–15% extra, or to plan a 1-inch loose layer that compacts down to roughly ¾ inch. Splitting the base into thin lifts and compacting each one gives a much more accurate final thickness than pouring all the sand at once.
Is a US ton the same as a metric tonne of sand?
No. A US (short) ton is 2000 lb, while a metric tonne is 1000 kg, about 2204.6 lb. One US ton equals \( 2000 \div 2204.6 \approx 0.907 \) tonnes, so 2 US tons is only about 1.81 tonnes. This matters when comparing supplier quotes: always check whether the price is per ton or per tonne before ordering.