Bedding sand is the thin, level layer of coarse sand that pavers actually sit on — the screed you smooth out after the gravel base is compacted. This calculator gives you cubic yards of bedding sand for any patio size, with 10% waste built in for screeding and edge work.
How bedding sand volume is calculated
Same volume math as any rectangular fill:
order = sand × 1.10 (10% waste for screeding loss)
The 10% waste covers screeding overspread, sand pulled into joints during compaction, and the inevitable extra you scoop and don’t use. Order in cubic yards if you’re getting bulk; in 0.5 cu ft bags if you’re at the home center.
Why 1 inch is the magic number
The 1" bedding standard isn’t arbitrary — it’s what every major paver manufacturer (Belgard, Pavestone, Unilock, Techo-Bloc) specifies in their installation guides. Here’s why:
- Less than 1": Not enough material to screed flat over an imperfect gravel base. Pavers ride high spots and create dips.
- More than 1.5": Sand consolidates over time. A 2" sand layer can settle 1/4"–1/2" within a year, causing pavers to sink unevenly. Once settling starts, the only fix is to pull up the patio and re-screed.
Coverage at 1" depth
For quick reference, one cubic yard of sand covers:
- 324 sq ft at 1" depth (paver bedding standard)
- 162 sq ft at 2" depth
- 108 sq ft at 3" depth
So a typical 12×10 ft patio (120 sq ft) needs about 0.4 cu yd of bedding sand, or ~5–6 standard 0.5 cu ft bags.
Bagged vs bulk for sand
Bagged coarse concrete sand runs $4–6 per 0.5 cu ft bag. That’s $216–$324 per cubic yard equivalent. Bulk delivered runs $30–$60 per cubic yard. For anything over 0.5 cubic yards (about 7 bags), bulk pays for itself even with delivery.
The catch with bulk sand: you need somewhere dry to dump it. Wet bedding sand is a nightmare to screed — it clumps and won’t level. If you’re getting bulk, time the delivery for a dry weather window, or have a tarp ready.
Don’t forget the polymeric sand
This calculator only handles bedding sand — the layer under the pavers. After the pavers are laid, you’ll also need polymeric sand to fill the joints between them. Polymeric sand is sold separately by the bag (typically 50 lb) and covers 75–100 sq ft per bag depending on joint width.
For your patio, calculate bedding sand here, lay the pavers, then pick up polymeric sand for the joints. Two different products, two different jobs.
Frequently asked questions
What kind of sand do I use under pavers?
Coarse concrete sand (also called bedding sand or ASTM C-33 sand) — angular grains that lock together but allow tiny height adjustments during installation. Do not use play sand or mason's sand — they're too fine, drain poorly, and wash out over time.
How thick should the sand layer be?
1 inch is the industry standard, screeded perfectly level before laying pavers. Anything thicker than 1.5" risks settling as the sand consolidates over time, leading to uneven pavers within a year. Thinner than 0.5" doesn't give enough room to adjust paver heights during installation.
Bedding sand vs polymeric sand — what's the difference?
Bedding sand goes under the pavers (the layer this calculator computes). Polymeric sand goes between pavers (the joints) after they're laid. Polymeric sand contains a binder that hardens when wet, locking pavers together. You need both — they're not interchangeable.
How much polymeric sand will I also need?
Polymeric sand coverage depends heavily on paver size and joint width. Rough rule: one 50 lb bag covers 75-100 sq ft of standard 6×9 pavers with 1/8" joints. For your 12×10 patio (120 sq ft), plan on 2 bags of polymeric sand on top of the bedding sand calculation.
Can I use stone dust instead?
Stone dust (also called screenings or quarry dust) is sometimes used as a paver base substitute, but it's not recommended as bedding sand. Stone dust holds water — pavers freeze-thaw heave more in cold climates. Stick with washed coarse concrete sand for the bedding layer.