Paver Base Gravel Calculator

Estimate the crushed gravel base needed under pavers. Enter the area and base depth to get cubic yards and tons, including a compaction allowance.

base (yd³, compacted)

tons

bags (0.5 ft³)

Enter values to see your estimate.

How to Calculate Gravel Base for Pavers

Change the calculator above and watch every figure and the diagram below update live.

Top-down view (area × depth)

Step 1 · Area

20 ft × 10 ft = 200 ft²

Step 2 · Volume (× depth, ÷ 27)

200 ft² × 0.33 ft ÷ 27 = 2.47 yd³

3.46

tons (× 1.4)

134

bags (÷ 0.5 ft³)

These figures update automatically as you change the calculator above.

Paver base coverage

Approximate coverage of one cubic yard of gravel at common depths.

Approximate coverage of one cubic yard of gravel at common depths.
Depth	Coverage per yd³	Relative coverage
1"	324 sq ft	100%
2"	162 sq ft	50%
3"	108 sq ft	33%
4"	81 sq ft	25%
6"	54 sq ft	17%

Drag to explore coverage at a given depth 3 in

At 3 inches deep, one cubic yard of gravel covers 108 sq ft.

How to calculate paver base

Paver base is calculated as a volume. Measure the area, choose the base depth, and convert the result to cubic yards and tons:

Measure the excavated area in feet. Unilock recommends extending the base past the paver edge by a distance equal to the base depth, so a 20 × 10 ft patio with a 6-inch base is excavated to 21 × 11 ft (Unilock).
Choose the base depth in inches (see the table below).
Cubic yards = length (ft) × width (ft) × depth (in) ÷ 324.
Tons = cubic yards × about 1.4–1.5. Dense-graded base is on the heavier side once compacted, so confirm the figure with your supplier.
Add a compaction allowance of 10–15%. The calculator above includes this as a setting.

Worked example: a 12 × 12 ft patio with a 4-inch base. The excavated area is 13 × 13 ft = 169 sq ft. 169 × 4 ÷ 324 = 2.09 yd³. Add 15% for compaction: 2.40 yd³, roughly 3.4–3.6 tons.

How deep should a paver base be?

Unilock publishes two sets of ranges, a DIY guide and a more conservative technical guide:

Use	Unilock DIY guide	Unilock Basic Tech Guide
Patios and walkways	4–6 in	6–8 in
Driveways	8–12 in	10–14 in
Bedding layer (sand or 1/8" chip)	about 1 in

Use the deeper end of the range on clay, poorly drained or frost-prone soil. Unilock notes that clay bases need deeper excavation for drainage. Sources: Unilock DIY guide, Unilock Basic Tech Guide.

Paver base material: what to use

Unilock's tech guide specifies 3/4-inch crusher run gravel or 3/4-inch clear stone for the base (Unilock).

Crusher run (also called dense grade, #411, road base or quarry process) is crushed stone mixed with fines. It compacts into a very firm layer.
Clear stone (such as #57) has no fines. It drains much faster, but does not lock as tightly.
Avoid stone dust or limestone screenings as the base. Unilock warns that the fines trap water.

Typical delivered prices: crusher run $24–$34 per ton and crushed limestone $30–$38 per ton (HomeGuide, 2026).

Paver base vs paver sand

These are two separate layers, and a paver installation needs both:

Paver base is the thick, compacted crushed-stone layer that carries the load and drains water. It is 4–14 inches deep depending on use.
Paver sand (bedding) is a thin layer, about 1 inch of coarse sand or 1/8-inch chip, screeded flat on top of the base. Unilock's DIY guide says the bedding layer should not be compacted before the pavers are laid.

For bedding sand, a 1-inch layer needs about 0.31 yd³ per 100 sq ft (100 × 1 ÷ 324).

Paver base quantity chart

Patio size	4 in base	6 in base	8 in base
10 × 10 ft	1.23 yd³	1.85 yd³	2.47 yd³
12 × 12 ft	1.78 yd³	2.67 yd³	3.56 yd³
16 × 16 ft	3.16 yd³	4.74 yd³	6.32 yd³
20 × 20 ft	4.94 yd³	7.41 yd³	9.88 yd³

The chart covers the paver area only. Add the edge extension and 10–15% for compaction. For a step-by-step installation guide, see paver base explained. For bag counts, see how many bags of gravel you need.

Paver Base FAQs

How much gravel base do I need for pavers?

Use a 4–6 inch base. Calculate area × depth ÷ 27 for cubic yards, then add 10–15% because crushed base compacts.

How deep should a paver base be?

About 4 inches for walkways and patios, and 6 inches or more for driveways or areas with vehicle traffic.

What gravel is used under pavers?

Crusher run or dense-grade aggregate (with fines) compacts into a solid, level base under the bedding sand.

Do I add sand on top of the gravel?

Yes, a 1 inch bedding sand layer goes over the compacted gravel base before you set the pavers.

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