Paver Base Calculator
Work out the crushed-stone base and bedding sand that go under pavers. Pick what the pavers are for, enter the area, and get the base in cubic yards and tons (plus 0.5 ft³ bags), and the 1 in bedding sand in cubic feet and bags. The example is a 20 × 16 ft patio on a 6 in base.
How to use the paver base calculator
- Enter the patio, walk or driveway size. Add an area for each extra section.
- Choose What the pavers are for. It sets the compacted base depth: 6 in for walks and patios, 8 in for driveways (ICPI's 6–8 in minimum on firm soil) and 12 in for heavy vehicles or soft or clay soil. You can type your own depth.
- Keep the compaction allowance at about 15% so the loose gravel you order compacts down to the full depth.
- Read the headline: base gravel in cubic yards and tons, plus the 1 in of bedding sand. Bag counts for both are under the result.
- Enter your paver size too if you want the paver count; it doesn't change the base.
How paver base is calculated
Pavers sit on two layers: a compacted crushed-stone base, and a thin screeded layer of bedding sand on top.
- Base (ft³) = area × base depth (in) ÷ 12 × (1 + compaction allowance)
- Base tons = ft³ ÷ 27 × density (about 1.5 tons per yd³)
- Base bags = ft³ ÷ 0.5, rounded up (a 50 lb bag of paver base holds about 0.5 ft³)
- Sand (ft³) = area × 1 in ÷ 12, and bags = ft³ ÷ 0.5
The compaction allowance is there because dense-graded base loses volume when compacted. Suppliers quote 10–25%; we default to 15%, editable.
Worked example: a 20 × 16 ft patio on a 6 in base
This is the patio loaded above.
- Area: 20 × 16 = 320 ft².
- Base: 320 × 6 ÷ 12 = 160 ft³. Add 15% for compaction: 184 ft³, which is 6.81 yd³.
- Base weight at 1.5 tons per yd³: 10.22 tons, or 368 bags of 0.5 ft³.
- Bedding sand: 320 × 1 ÷ 12 = 26.67 ft³, which is 54 bags of 0.5 ft³.
- Pavers (6 × 9 in, 10% waste): 939.
Over 350 bags of base is a strong case for bulk: 10 tons of crusher run is one delivery. The sand is often bought in bags because the quantity is small.
How deep should paver base be?
The Interlocking Concrete Pavement Institute's Tech Spec 10 sets the minimum compacted base for residential work: 4–6 in for walks and patios and 6–8 in for driveways on firm, well-drained soil. Where heavy vehicles use the driveway (delivery trucks, an RV, a loaded trailer), or the ground is soft clay that stays wet, plan on 8–12 in, ICPI's range for streets and weak soils. On top goes a 1 in layer of bedding sand, screeded flat but not compacted before the pavers are laid.
In the calculator, Walk or patio uses 6 in, Driveway 8 in and Heavy vehicles, or soft or clay soil 12 in, the deeper end of each range. In cold climates, also check your local frost depth. The base should extend past the edge of the pavers so the edge restraint sits on it, which adds a little area.
Paver base depth by use: base and bedding sand per 100 ft²
| Use | Compacted base | Loose base yd³ per 100 ft² | Tons per 100 ft² | 0.5 ft³ base bags per 100 ft² | 1 in bedding sand: 0.5 ft³ bags per 100 ft² |
|---|---|---|---|---|---|
| Walk or patio (ICPI minimum) | 4 in | 1.42 | 2.13 | 77 | 17 |
| Walk or patio on clay or in a cold climate | 6 in | 2.13 | 3.19 | 115 | 17 |
| Residential driveway (ICPI minimum, firm soil) | 6 in | 2.13 | 3.19 | 115 | 17 |
| Residential driveway (calculator default) | 8 in | 2.84 | 4.26 | 154 | 17 |
| Heavy vehicles, or soft or clay soil | 12 in | 4.26 | 6.39 | 230 | 17 |
Base volumes include 15% extra so the compacted layer reaches full depth (an editable assumption; ask your supplier). Base gravel at 1.5 tons per yd³. Depths from ICPI Tech Spec 10: 4–6 in for walks and patios, 6–8 in for driveways on firm soil, 8–12 in for heavy vehicles or weak soil.
Base installation tips
- Dig deep enough. Excavation depth = base + 1 in sand + paver thickness, minus any height the patio should sit above the ground.
- Compact in lifts. Spread and compact the base in layers of a few inches with a plate compactor; one thick layer won't compact all the way down.
- Slope for drainage. Give the base a gentle fall away from the house so water runs off the finished patio.
- Don't use sand as the base. Sand is only the 1 in bedding layer; the load-bearing base is compacted crushed stone.
- Extend the base past the edges. Run the base several inches beyond the pavers so the edge restraint has firm support.
Frequently asked questions
How much paver base do I need?
Multiply the area by the compacted base depth, add about 15% for compaction and divide by 27 for cubic yards. A 20 × 16 ft patio on a 6 in base needs about 6.8 yd³, or 10.2 tons of crushed stone.
How deep should paver base be?
ICPI gives 4–6 in of compacted base for walks and patios and 6–8 in for residential driveways on firm soil. For heavy vehicles, or soft or clay soil, use 8–12 in.
How many bags of paver base per 100 square feet?
At 4 in compacted with a 15% allowance, about 77 bags of 0.5 ft³ per 100 ft²; at 6 in, about 115 bags. For large areas, bulk gravel is far cheaper.
How much sand goes under pavers?
A 1 in screeded layer (ICPI): 8.33 ft³ per 100 ft², which is 17 bags of 0.5 ft³.
Can I use sand instead of gravel for paver base?
No. The load-bearing layer is compacted crushed stone; sand is only the 1 in bedding layer on top. Pavers laid on deep sand rut and sink.
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