Paver installation has two sand-related decisions that most people only think about as one: the crushed stone base layer, and the sand bedding layer. Each serves a completely different purpose, and sizing them correctly is what keeps a patio or walkway from shifting and settling years after installation.
Here is exactly how to calculate both.
The two layers you need
Layer 1: Crushed stone base. This is the structural layer. It distributes the weight of the pavers and traffic, provides drainage, and prevents frost heave. This is almost always crushed gravel or crushed stone, not sand.
Layer 2: Bedding sand. This goes on top of the compacted base. It is 1 inch thick and gives you the ability to fine-tune the level of each paver during installation. Polymeric sand fills the joints between pavers after installation, which is a third material entirely.
Most people think they just need “sand for pavers.” They actually need gravel for the base, sand for the bed, and polymeric sand for the joints. These are three separate orders.
How to size the crushed stone base
Base depth depends on how the surface will be used.
Foot traffic only (patios, walkways): 4 inches of compacted crushed stone is sufficient in most regions.
Vehicle traffic (driveways, parking pads): 6 to 8 inches of compacted crushed stone. Less than 6 inches and vehicle weight will eventually cause settling.
Cold climates with deep frost: Add 2 inches to whichever depth applies to your use case.
To calculate cubic yards of base material:
Cubic yards = (length ft x width ft x depth in) / 324
For a 12 by 16 foot patio with a 4-inch base:
- (12 x 16 x 4) / 324 = 768 / 324 = 2.4 cubic yards
- Add 10 percent for compaction: 2.4 x 1.10 = 2.6 cubic yards
Crushed stone compacts about 10 to 15 percent under a plate compactor, so you need more loose material than the final compacted depth.
How to size the bedding sand
The bedding sand is always 1 inch deep. This is the standard across all paver manufacturers. Do not go thicker: a bedding sand layer deeper than 1 inch is unstable and will cause pavers to rock.
To calculate cubic yards of bedding sand:
Cubic yards = (length ft x width ft x 1 in) / 324
For the same 12 by 16 foot patio:
- (12 x 16 x 1) / 324 = 192 / 324 = 0.59 cubic yards
In this case, you need just over half a cubic yard of bedding sand. Most sand suppliers have a half-yard minimum for delivery, so you would order 1 cubic yard.
Polymeric sand for joints
After pavers are set and leveled, the joints between them get filled with polymeric sand. This is a different product from bedding sand: it contains binders that harden when wet, locking the pavers in place and blocking weeds.
Coverage for joint sand depends on paver size and joint width. Narrow joints (1/4 inch) on large pavers use less. Wide joints (1 inch) on small pavers use significantly more. As a rough guide:
| Paver size | Typical joint sand coverage per 50 lb bag |
|---|---|
| 4 x 8 inch | 25 to 35 sq ft |
| 6 x 6 inch | 40 to 55 sq ft |
| 12 x 12 inch | 80 to 100 sq ft |
| 12 x 24 inch | 100 to 130 sq ft |
These are estimates. The coverage rate on the bag is more accurate for your specific product.
A complete material list for a 12 x 16 patio
| Material | Amount |
|---|---|
| Crushed stone base (4 in) | 2.6 cubic yards |
| Bedding sand (1 in) | 0.6 cubic yards (order 1 yd) |
| Polymeric joint sand (for 6x6 pavers at 1/4 in joint) | 6 to 7 bags |
| Pavers | Patio area + 10 percent waste |
The most common paver installation mistake
Skipping or thinning the base to save money. A thin base settles unevenly, and once pavers shift, releveling requires pulling them up and starting the base over. The extra cost of a proper 4-inch compacted base is trivial compared to rebuilding the project in 3 years.
Use the paver sand calculator to get exact quantities for your project dimensions, including both the base and bedding layers. For any additional sand needs around the project, the sand calculator handles bulk quantities in cubic yards or tons.
Frequently Asked Questions
What type of sand goes under pavers?
Coarse concrete sand (also called sharp sand or builder’s sand) for the bedding layer. It has angular grains that resist compaction under the paver weight while still allowing fine adjustment. Do not use play sand or mason sand under pavers; the fine, rounded grains compact too easily and cause uneven settling. The bedding sand layer should be exactly 1 inch deep after compaction.
What is polymeric sand and when do I need it?
Polymeric sand is regular sand mixed with a polymer binder that activates with water and hardens into a semi-flexible joint filler. It resists ant infiltration, weed germination, and erosion better than standard joint sand. Use it for patios, walkways, and driveways where appearance matters. It costs more than regular sand but typically lasts 8 to 10 years before reapplication versus 2 to 3 years for standard sand.
How thick should the sand layer be under pavers?
Exactly 1 inch of compacted bedding sand. More than that and the pavers will not seat firmly and will rock. Less and there is not enough material to level small variations. The sand is screeded to a flat, consistent 1-inch depth before laying pavers. The 4 to 6 inches of crushed stone base beneath the sand layer does the structural work; the sand is only for leveling.
Can I use regular play sand to fill paver joints?
Play sand is too fine and rounded to stay in joints well. Wind blows it out, rain washes it away, and ants excavate it easily. Regular coarse sand stays better, but polymeric sand is the right choice for joints in installed paver systems. For temporary filling or for projects you will redo, regular coarse sand works; for permanent installations, use polymeric.
How long does polymeric sand take to harden?
Initial set takes 24 to 48 hours after activation with water. Full cure takes about 2 weeks. During the curing period, keep foot traffic minimal and avoid letting water pool on the surface. Rain in the first 24 hours after activation can wash the polymers out of the joints before they set. Check the weather forecast before applying polymeric sand.
What happens if the sand bedding layer is too thick?
Pavers set on too much bedding sand sink unevenly as the sand consolidates under foot traffic. The paver surface becomes wavy, and the gaps between pavers open up or close in irregular ways. Fixing it requires pulling the pavers, re-establishing the correct base, and re-screeding the bedding sand. Getting the 1-inch depth right during installation prevents the need to redo the work later.