How this paver base calculator works
Everything under the pavers is two separate orders — a structural crushed-stone base and a thin sand screed — and each is its own volume × density:
sand tons = area × 1″ ÷ 12 ÷ 27 × 1.35 · + waste, up to the ¼ ton
Both layers carry the same waste allowance and round up to the quarter ton a quarry will weigh out. At the defaults — a 12 × 12 ft patio on 4 in of base — that’s 2.75 tons of crushed stone and 0.75 tons of sand, about $154 before the pavers; the line-by-line math is in the worked example below.
What are the layers under pavers?
A paver installation is a stack of six layers, and only the top one shows: subgrade, fabric where the ground is bad, compacted base, screeded sand, the pavers, and the edge that holds it all in. What each layer does:
Subgrade
The native soil, excavated to depth and compacted. Every wave in the subgrade telegraphs up through base, sand and pavers eventually — flatten it now or chase it forever.
Geotextile fabric
On clay and wet sites, a woven separation fabric goes down first so the base stone can’t pump into the mud. Skip it on clean draining ground; never substitute it for depth.
Compacted base
The structure: 4–6 in of dense-grade crushed stone for foot traffic, 8–12 in for cars, placed in 2–3 in lifts with a plate compactor pass on every lift. This layer spreads loads, drains water and decides whether the patio is flat in five years.
Bedding sand
One screeded inch of coarse concrete sand — a setting cushion, not a structural layer. Some installers screed stone dust instead; ICPI guidance stays with washed concrete sand, and so does this calculator’s default.
The pavers
Concrete, clay or natural stone, 2⅜ in thick in the common formats. They’re a separate order priced per square foot — this tool builds what’s underneath them.
Edge restraint and joint sand
Spiked plastic or steel restraint pins the field together at the perimeter, and polymeric sand swept into the joints locks the surface. Both come after laying, both by the piece and the bag.
What base material for pavers?
Dense-graded crushed stone is the default answer; the alternatives exist for specific reasons — permeability, budget, or the last quarter inch of screed:
- Dense-grade / road base: ¾ in minus with fines (CA-6, Class 5, 21A, ABC by region) — compacts near-solid; the standard. The road base calculator runs it at compacted density for bigger projects.
- Open-graded #57: clean stone, no fines — the base for permeable paver systems that drain through. Different build, different bedding (chip stone, not sand).
- Recycled crushed concrete: compacts like dense-grade at a lower price — a legitimate budget base under patios.
- Stone dust alone: screeds beautifully but holds water — fine as a thin bedding choice in some regions, never as the structural base.
- Pea gravel and river rock: never. Round stone can’t lock, so it rolls under load forever.
| Item | Typical range |
|---|---|
| Crushed base, per ton | $35–60 |
| Bedding sand, per ton | $30–50 |
| Geotextile, per ft² | $0.15–0.50 |
| Edge restraint, per lin ft | $2–4 |
| Polymeric sand, 50 lb bag | $20–40 |
How much gravel and sand under pavers?
Table 2 runs common patio sizes through the engine at the standard 4 in base and 1 in screed; Table 3 is the depth spec by duty.
| Patio | Area | Base | Sand |
|---|---|---|---|
| 10 × 10 | 100 ft² | 2 t | 0.5 t |
| 12 × 12 | 144 ft² | 2.75 t | 0.75 t |
| 16 × 16 | 256 ft² | 5 t | 1.25 t |
| 20 × 20 | 400 ft² | 7.75 t | 2 t |
| Use | Base | Sand |
|---|---|---|
| Walkway | 4″ | 1″ |
| Patio | 4–6″ | 1″ |
| Driveway | 8–12″ | 1″ |
How to measure for paver base
Measure the finished patio, then think in layers downward — the excavation is the sum of everything you’re about to buy. Dimension fields take feet-inches (12, 12 ft 6 in) or metric (4 m).
- Measure the patio’s length and width — the paver field plus a 6 in working apron each side if you want the base to extend past the edge restraint, which good installs do.
- Set the base depth by duty: 4 in walkways and small patios, 6 in big patios or iffy soil, 8–12 in anywhere a car will sit.
- Leave the sand at 1 in. It’s a screed course; making it deeper makes the patio worse.
- Set waste at 10% — compaction consumes volume; go 15% over soft or clay subgrade along with the deeper base.
- Enter both per-ton prices from the quarry — base and sand usually ride the same truck, one delivery fee.
- Check your dig depth: base + 1 in sand + paver thickness (commonly 2⅜ in) minus the height the patio should sit above grade — that’s the excavation, and the spoil volume leaving the site.
Worked example: base for a 12 × 12 ft paver patio
The defaults, worked line by line — 144 ft², 4 in of base under 1 in of sand, 10% waste, $45 stone over $40 sand:
base = 144 × (4 ÷ 12) = 48 ft³ = 1.78 yd³
base tons = 1.78 × 1.4 = 2.49 × 1.10 = 2.74 → order 2.75 t
sand = 144 × (1 ÷ 12) = 12 ft³ = 0.44 yd³
sand tons = 0.44 × 1.35 = 0.6 × 1.10 = 0.66 → order 0.75 t
cost = 2.75 × $45 + 0.75 × $40 = $123.75 + $30 ≈ $154
Notice the ratio: the base outweighs the sand almost four to one, and that’s at patio depth — at driveway depth it’s ten to one. When a paver bid looks thin, the base tonnage is the first place to check. Dig depth here: 4 + 1 + 2⅜ ≈ 7⅜ in below finished grade.
What this paver base estimate doesn’t include
The calculator prices the two layers of aggregate. The patio above and the hole below have their own lines:
- The pavers. Commonly $2.50–8 per ft² in concrete, more in clay and stone — usually the biggest material line.
- Excavation and haul-off. A 12 × 12 patio dug 7 in deep sends roughly 3 yards of spoil somewhere, and dumping soil costs money.
- Geotextile fabric on soft ground, under the base.
- Edge restraint and spikes around the perimeter.
- Polymeric joint sand swept and watered in after laying.
- Plate compactor rental — about $90–120 a day, used on every base lift and again over the laid pavers.
- Labor. Hired paver installation commonly lands at $10–25 per ft² all-in, base included — the aggregate is the cheap part.
Paver base FAQ
How much paver base do I need?
A 4 in compacted base under a 12 × 12 ft patio takes 2.75 tons of crushed stone with 10% waste, plus 0.75 tons of bedding sand for the 1 in screed course. The calculator scales both layers from your dimensions and depth, in tons and in 0.5 ft³ bags.
How deep should paver base be?
4–6 inches of compacted gravel for patios and walkways, 8–12 inches where vehicles drive, always on top of undisturbed or compacted subgrade. The sand on top stays at 1 inch no matter what — it beds the pavers, it doesn’t add structure.
What kind of gravel goes under pavers?
¾ in minus crushed stone with fines — sold as paver base, dense-grade aggregate, or road base (CA-6 / Class 5 / 21A depending on your region). The angular pieces and stone dust lock tight under a plate compactor. Round pea gravel never locks and doesn’t belong under pavers.
How much base for a paver driveway?
Vehicle duty means 8–12 inches of compacted base: a single 20 × 20 ft parking apron at 10 in takes about 19.25 tons of crushed stone with 10% waste — dump-truck territory, not pallets. The 1 in sand screed stays the same as a patio.
Can I lay pavers on just sand without gravel?
Not if you want them flat next spring. Sand alone shifts, washes out, and ruts under point loads; the compacted gravel base is what spreads loads and drains water. The exception is a stepping-stone path where movement doesn’t matter.
Do I need landscape fabric under paver base?
On clay, silt or chronically wet ground, yes — a woven geotextile keeps the base stone from pumping down into the subgrade and is the cheapest insurance on the job. On clean sandy or gravelly ground it adds little. It goes under the base, never under the sand.
How many bags of paver base do I need?
The default patio takes about 106 bags of base and 27 of sand at 0.5 ft³ a bag — which is why bulk delivery wins past roughly a ton. The bag line under the drawing recomputes for your job; compare the pallet price against a bulk drop before loading carts.
How much does paver base cost?
Crushed base typically runs $35–60 a ton and bedding sand $30–50 in 2026, delivery extra. The default 144 ft² patio lands around $154 in base materials at the editable default prices — the pavers themselves are the bigger line.
Sources and standards
The layer depths and materials here follow the interlocking-pavement industry’s own specs:
- ICPI guidance (Interlocking Concrete Pavement Institute): the 1 in screeded bedding standard, compacted-lift base practice, and edge restraint requirement.
- ASTM C33: the concrete-sand gradation specified for bedding.
- ASTM D2940 and regional DOT gradations (CA-6, Class 5, 21A): what “dense-grade base” means at your quarry.
- The scale ticket: 1.4 and 1.35 t/yd³ are estimating densities — the weighed load governs the invoice.
Embed this paver base calculator on your site
Run the paver base calculator on your own site, free. Paste the snippet where you want it; the visible credit link is the only condition.