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Pea Gravel Calculator

Estimate smooth river rock and pea gravel quantities with optimal walking depth guidelines.

Pea Gravel Calculator Interactive Tool

Interactive Calculator

Enter your project dimensions below. Results update instantly.

2.5 to 3 inches recommended for pathways
typical value, change to match your productSettling into soil and boundary edge allowance
typical value, change to match your productPea gravel typically weighs 1.3 to 1.4 tons/yd³
typical value, change to match your productStandard bag weight for bagged pea gravel

Results

Base Volume

1.54 cu yd

41.7 cu ft (before compaction)
Adjusted Volume to Order

1.7 cu yd

Includes +10% compaction buffer
Weight in Tons

2.29 tons

At 1.35 tons/yd³
Bags to Buy

92

50-lb retail bags
Surface Area: 200 sq ft. Ideal depth for pathways and decorative coverage.

Pea Gravel Volume Formula

Volume (cu ft) = Area (sq ft) × (Depth (in) ÷ 12) | Tons = (cu ft ÷ 27) × 1.35 tons/yd³ × (1 + Waste % ÷ 100)

Formula Variables:

  • 1.35 tons/yd³:Typical density of 3/8" smooth rounded pea gravel (~2,700 lbs/cu yd).
  • Recommended Depth:Keep depth between 2.0" and 2.5" for stable foot traffic.

Rounded pea gravel does not interlock like crushed stone. Depths exceeding 3 inches create loose, shifting footing like dry sand.

Step-by-Step Worked Example

Example: Circular fire pit area (14 ft diameter) at 2.5 inches depth

Installing 3/8" rounded pea gravel in a 14-foot circular fire pit lounge area.

Area:153.94 sq ft (π × 7²)
Depth:2.5 inches
Waste:10%
  1. Calculate area: π × 7 ft × 7 ft = 153.94 sq ft.
  2. Calculate volume: 153.94 × (2.5 ÷ 12) = 32.07 cu ft.
  3. Convert to cubic yards: 32.07 ÷ 27 = 1.188 cu yd.
  4. Add 10% waste buffer: 1.188 × 1.10 = 1.31 cu yd.
  5. Calculate tons: 1.31 cu yd × 1.35 tons/yd³ = 1.77 tons (3,540 lbs).
  6. Bag count: 3,540 lbs ÷ 50 lbs/bag = 71 bags.
Order 1.35 cubic yards (or 1.8 tons). If buying retail, purchase 71 fifty-pound bags.

Input Explanations & Measurement Guidelines

Surface Area

Typical: 100 to 250 sq ft

Square footage of the pathway or outdoor seating area.

Depth

Typical: 2.5 inches

Recommended 2.0 to 2.5 inches. Over 3 inches makes walking difficult.

Assumptions & Limitations

  • Assumes heavy-duty woven landscape fabric is installed underneath to stop stone from migrating into the soil.
  • Assumes rigid edging is installed along borders to contain loose rounded stones.

Safety & Professional Notes

  • Pea gravel can be slippery on sloping paths. Avoid using pea gravel on inclines steeper than a 5% grade.
Recommended Guide · 5 min read

How Much Gravel Do I Need? Coverage Charts, Density & Depth Chart

A reference guide for homeowners estimating gravel requirements. Features coverage charts showing how many square feet 1 cubic yard or ton covers at various depths.

Read Guide

Frequently Asked Questions

What is the best depth for a pea gravel patio?

The ideal depth is 2.5 inches. Less than 2 inches will expose your landscape fabric; greater than 3 inches creates a beach-like sinking effect when walking.

Does pea gravel compact?

No. Because the stones are naturally smooth and rounded river rock, they do not lock together. They remain loose and shifting.

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