BuildingPaver Base Calculator

Paver Base Calculator

How much paver base do I need? Enter your patio or driveway dimensions to get gravel tons, sand quantities, and cost estimates with compaction factors.

Project Dimensions

Accounts for soil settling and compaction loss

10% typical for most materials

Ready to calculate

Enter your project dimensions

Last updated March 31, 2026 by our expert review team

Recommended Base Depths

4"

Walkways

Foot traffic

6"

Patios

Light use

8"

Driveways

Vehicles

10"

Heavy duty

Trucks

Expert Contributors

RW
Creator
Ruth Wairimu
Landscape Architect
H
Expert Review
Hawkin
Certified Cost & Estimating Professional

Pro Tips

1

Compact in 2-inch lifts with a plate compactor (5,000+ lb force) to reach 95% Modified Proctor density. Single-pass compaction leaves the bottom half loose.

2

Use ASTM #57 or #21A crushed stone with angular fines (3/4" minus). Never use river gravel, which is round and will not interlock.

3

Bedding sand must be ASTM C-33 coarse concrete sand. Play sand and mason sand shift under pavers and cause lippage within the first season. Use our paver sand calculator for exact quantities.

4

Grade your base at 1/4 inch per foot (2% slope) away from the foundation. The ICPI technical resources detail proper drainage slopes. Verify with a level before laying sand.

5

Extend your base 6-12 inches beyond the paver edge for edge restraints. ICPI Tech Spec #3 requires at least 6 inches past the paver field.

6

Install non-woven geotextile fabric on clay or silt soils. This prevents base material from migrating downward over 3-5 years.

7

Need decorative stone for the finished surface? Check our stone calculator or sand calculator for additional materials.

How the Calculator Works

Our paver base calculator determines the amount of gravel base and bedding sand needed for your project, following ICPI (Interlocking Concrete Pavement Institute) installation guidelines. It calculates two separate material layers: the structural gravel base (1.4 tons/yd³ for crushed stone per ASTM C29) and the bedding sand layer (1.35 tons/yd³ for ASTM C-33 concrete sand). The calculator applies both a waste factor (10-15% for edge losses and uneven subgrade) and a compaction factor (20% standard, since loose crushed stone compresses approximately 20-25% to reach 95% Modified Proctor density). Bedding sand does not receive a compaction factor because it is screeded to a precise 1-inch depth, not mechanically compacted.

Formula

Area × (Depth ÷ 12) ÷ 27 = Cubic Yards

Cubic Yards × 1.4 = Tons (gravel)

Quick Reference

Gravel weight
~1.4 tons/yd³
Sand weight
~1.35 tons/yd³
Standard sand bed
1 inch
Compaction factor
~95%

Frequently Asked Questions About Paver Base

What gravel for a paver base?

Angular crushed stone, 3/4" minus (#21A or dense-grade). ICPI recommends ASTM D2940 with 10-15% fines for optimal compaction. See ICPI technical papers for full specs.

Can I use regular sand for bedding?

No. Only ASTM C-33 coarse concrete sand works. Mason and play sand shift under pavers, causing lippage in 6-12 months.

Do I need geotextile fabric?

Yes on clay, silt, or water-holding soils. It prevents base stone from migrating into soft subgrade. Optional on sandy soils.

How deep should the gravel base be?

4" for walkways, 6" for patios, 8-10" for driveways, 12"+ for commercial. Add 2" on clay soils.

How much does base material cost?

Gravel: $0.50-1.00/sq ft at 6" depth. Sand adds $0.15-0.25/sq ft. A 200 sq ft patio runs $130-250 total.

Can I skip the sand layer?

No. The 1" sand bed levels pavers and absorbs base variations. ICPI Tech Spec #2 requires a sand setting bed.

How do I check compaction?

Walk in hard-soled shoes. No footprints deeper than 1/8". The ICPI standard is 95% Modified Proctor density.

What is the compaction factor?

Plan for 20-25% loss. For 6" compacted base, spread about 7.5" of loose material. Our calculator handles this automatically.

Paver Base Mistakes That Cost You Money

Using round gravel instead of angular stone

Round aggregates don't interlock. ICPI requires angular crushed stone (#21A or 3/4" minus) for a stable, load-bearing base.

Making the sand bed too thick

Keep bedding sand at 1 inch compacted (1.5" loose, then screed). Fix unevenness in the gravel layer, not with extra sand.

Forgetting to slope for drainage

Grade 1/4 inch per foot (2%) away from the house. A flat patio ponds water, causing efflorescence and frost heave.

Skipping edge restraints

Without them, pavers shift 1-2 inches per year. Install Snap Edge or aluminum L-channel on all sides before final compaction.

Compacting the full depth in one pass

Compact 2-3 inches at a time. An 8-inch single-pass leaves the bottom loose, causing settling in the first winter.

Not extending base past paver edge

Extend gravel 6-12 inches beyond pavers on all sides per ICPI. This supports edge restraints and prevents rain undermining.

Paver Base Estimates for Common Projects

Backyard Patio

12×16 ft, 6" base
2.8 tons gravel + 0.35 tons sand~$120

192 sq ft patio with #21A crushed stone base and ASTM C-33 bedding sand. With 20% compaction factor and 10% waste, total material cost was under $120. Geotextile fabric added $30 for the clay subgrade. Completed in one weekend.

Driveway Extension

10×24 ft, 8" base
4.7 tons gravel + 0.44 tons sand~$156

240 sq ft driveway apron using 8 inches of compacted base for vehicle traffic per ICPI standards. The extra base depth handles a daily-use SUV and occasional delivery trucks. Aluminum edge restraints ($45) keep pavers locked.

Garden Walkway

4×30 ft, 4" base
1.1 tons gravel + 0.22 tons sand~$41

120 sq ft garden walkway needing only 4 inches of base (foot traffic only). The narrow width required careful edge restraint on both sides. Completed the base prep in 3 hours, including one trip to the landscape supply yard.

Important Disclaimer

These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.