Calculator

Paver Base Calculator Gravel Base & Bedding Sand

Enter your paver area and gravel base depth to get how much base gravel and 1-inch bedding sand you need, in cubic yards, tons, and bags.

A 120 sq ft paver patio with a 4-inch gravel base needs about 1.48 cubic yards (roughly 2.07 tons) of compacted crushed stone plus about 0.37 cubic yard of bedding sand for the 1-inch screed layer — that is around 20 of the half-cubic-foot bags. Enter your area and your intended base depth below for an exact estimate.

Your project

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Enter your measurements above and click Calculate.

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How to measure for your paver base (gravel & sand) project

  1. Measure your paver area. Measure the length and width of the patio or walkway in feet and multiply to get square footage. For an L-shaped or irregular area, split it into rectangles, calculate each, and add them together. Make the area a few inches larger on each side than the pavers themselves — you will compact the base beyond the paver edge.
  2. Choose your base depth. Enter the gravel base depth in inches. Use 4 inches for a standard patio or walkway; bump up to 6 inches for a driveway or in climates with heavy frost or clay soil that drains poorly. The calculator always adds a 1-inch bedding-sand layer on top of that gravel, which is standard practice.
  3. Read the gravel and sand totals, then order with waste. You will get base gravel in cubic yards and tons, plus bedding sand in cubic yards and half-cubic-foot bag counts. Add about 10% to both figures before ordering — compaction losses, uneven excavation, and slight over-digs always consume extra material.

How the paver base (gravel & sand) calculator works

base gravel (cu yd) = area × (depth_in ÷ 12) ÷ 27; bedding sand (cu yd) = area × (1 ÷ 12) ÷ 27

Both layers use the same volume formula: area (sq ft) × depth (ft) ÷ 27 = cubic yards. The gravel depth is whatever you enter (4 inches = 4 ÷ 12 ft); the bedding sand is always 1 inch (1 ÷ 12 ft). To convert gravel cubic yards to tons, multiply by 1.4 — that is the typical bulk density of compactable crushed stone. For a worked example, take a 100 sq ft patio at a 4-inch base: gravel = 100 × (4 ÷ 12) ÷ 27 = 100 × 0.333 ÷ 27 = 1.23 cubic yards, and 1.23 × 1.4 = 1.73 tons. The 1-inch sand layer adds 100 × (1 ÷ 12) ÷ 27 = 0.31 cubic yards — or about 17 half-cubic-foot bags.

Which type are you estimating?

Standard patio or walkway — compactable crushed stone base

The go-to sub-base for most DIY paver projects is compactable crushed stone — sold as "paver base," crusher run, #21A, or dense-grade aggregate depending on your region. It locks together when compacted, creating a firm, stable layer that resists shifting. This is the method the calculator defaults to: compact the stone in 2-inch lifts, then screed 1 inch of coarse bedding sand on top.

Enter: Enter your area and 4 in for the base depth (patios / walkways).

Driveway or heavy-load base

Driveways and areas that take vehicle weight need a deeper, stronger sub-base. The standard recommendation is 6 inches of compactable crushed stone, sometimes over a geotextile fabric to separate the stone from soft or clay subsoil. In cold climates with deep frost, local codes may call for 8–10 inches. Add about 10% for compaction loss.

Enter: Enter your area and 6 in (or your local requirement) for the base depth.

Permeable / open-graded base (clean #57 stone)

For a permeable paver system that drains water straight down, some installers skip the compactable stone and use open-graded clean crushed stone (#57 or similar) with no fines. Water passes freely through the voids. The depth math is the same, but you skip the traditional compaction step. Use a chip-stone or coarse ASTM #8 setting bed instead of sand.

Enter: Enter your area and your chosen base depth (typically 4–6 in).

The 1-inch bedding-sand layer

Regardless of what base material you use, the screed layer directly under the pavers should be coarse concrete sand (sometimes called "sharp sand" or ASTM C33 sand) — NOT polymeric sand, not pea gravel, and not play sand. It sits 1 inch thick before the pavers go down; after you set and compact the pavers it compresses slightly. The calculator already factors this in as a fixed 1-inch layer.

Enter: No separate input needed — the calculator always includes 1 in of bedding sand.

Cold-climate or clay-soil projects

Freeze-thaw cycles and poorly draining clay can heave or settle a paver base over time. In these conditions, dig deeper (6–8+ inches of gravel), ensure the sub-base grades away from structures for drainage, and consider a layer of geotextile fabric between the native soil and the gravel. The calculator handles any depth you enter.

Enter: Enter your area and 6–8 in (or your local frost-depth requirement) for the base depth.

Tips & ways to save

  • Compact the gravel base in 2-inch lifts — do not dump the full 4–6 inches and compact all at once. Each lift needs several passes with a plate compactor for a solid result.
  • Dig the area slightly wider than the paver footprint on all sides — the compacted base should extend 3–6 inches beyond the paver edge so the perimeter does not cave in.
  • Use coarse concrete sand (ASTM C33) for the 1-inch bedding layer, not fine play sand or polymeric sand. Fine sand can wash out or compact unevenly, leading to sunken pavers.
  • One cubic yard of compacted crushed stone weighs roughly 1.4 tons — order by the ton and ask your supplier for a delivery slip you can check against the calculator total.
  • Buy polymeric joint sand separately; it is not included in this estimate. Coverage varies by paver size and joint width — small pavers with 1/4-inch joints use far more than large-format pavers.

Paver base & bedding sand by patio size (4 in base, 1 in sand)

Paver base & bedding sand by patio size (4 in base, 1 in sand)
Patio areaBase gravel (cu yd)Base gravel (tons)Bedding sand (cu yd)
50 sq ft0.620.860.15
100 sq ft1.231.730.31
150 sq ft1.852.590.46
200 sq ft2.473.460.62
300 sq ft3.705.190.93

Base gravel assumes 4 inches compacted (use 6+ for driveways) at ~1.4 tons per cubic yard, plus a 1-inch bedding-sand layer. Polymeric joint sand is separate — see the FAQ.

Frequently asked questions

How much gravel do I need under pavers?
Use a 4-inch compacted gravel (crushed stone) base for patios and walkways, and 6 inches or more for driveways. A 100 sq ft patio needs about 1.23 cubic yards — roughly 1.73 tons — of base gravel at 4 inches.
How much paver sand do I need?
Spread a 1-inch bedding-sand layer over the compacted base: about 0.31 cubic yard per 100 sq ft, or roughly 17 of the 0.5 cu ft bags. That is separate from the polymeric sand that fills the joints.
What is the difference between bedding sand and polymeric sand?
Bedding (paver) sand is the 1-inch leveling layer under the pavers. Polymeric sand fills the joints on top and hardens when wetted. A bag of polymeric sand covers roughly 25–100 sq ft depending on paver size and joint width — small pavers and wide joints use much more.
How many tons of gravel do I need for a paver base?
Compactable crushed stone weighs about 1.4 tons per cubic yard. For a 100 sq ft patio at a 4-inch base you need roughly 1.23 cubic yards — about 1.73 tons. At a 6-inch base the same area needs about 1.85 cubic yards — roughly 2.59 tons. The calculator shows both cubic yards and tons for every size.
How deep should I dig for a paver patio?
Excavate deep enough for the gravel base, 1 inch of bedding sand, and the paver thickness itself. For a standard 2.375-inch paver on a 4-inch base, dig about 7–8 inches below the finished surface grade. Use 6 inches of base (8–9 inches total) for driveways or heavy-use areas.
Do I need to compact the gravel base?
Yes — compacting is essential. Loose gravel will settle unevenly after the pavers go down, causing dips and wobbles. Compact in 2-inch lifts with a plate compactor, making several passes each lift. A 4-inch base means two compaction lifts; a 6-inch base means three.
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Reviewed by the BackyardCalc editorial team. Figures are computed from the formula above and checked against manufacturer yields.

Estimates are guidance only — material quantities vary by project conditions. Always confirm with a professional before purchasing.