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Gravel · Pea Gravel

Pea Gravel Calculator

Smooth, rounded and barefoot-friendly — and lighter than other gravels, so its coverage math is its own. Depth presets match real applications.

MaterialsCalc Editorial TeamMaterialsCalc Editorial TeamConstruction Estimating EditorsJuly 15, 2026
Formula

Tons = ft² × (depth ÷ 12) × 96 ÷ 2,000 × (1 + waste)

96
loose pea gravel density (lb/ft³)

One ton of pea gravel covers ≈125 ft² at 2 in, 83 ft² at 3 in. Bags: one 0.5 ft³ bag covers 3 ft² at 2 in.

Pea Gravel Calculator

Paths, patios, play areas and drainage — tons, cubic yards and 0.5 ft³ retail bags in one result.

Deeper than 3 in gets hard to walk on — pea gravel shifts underfoot.

Coverage at a glance

At 96 lb/ft³ loose. Full tables at every depth in the pea gravel coverage guide.
DepthPer tonPer 0.5 ft³ bag
2 in — walkways≈125 ft²3.0 ft²
3 in — patios≈83 ft²2.0 ft²
4 in — loose fill≈62 ft²1.5 ft²
9 in — playground fall zone≈28 ft²0.67 ft²CPSC loose-fill guidance

Worked example: garden path

Worked example

A 40 ft long, 3 ft wide garden path — 2 in of pea gravel over 2 in of compacted stone dust.

  1. 1

    Pea gravel volume

    120 ft² × (2 ÷ 12) = 20 ft³

  2. 2

    Tons + 10%

    20 × 96 ÷ 2,000 × 1.10 = 1.06 tons

  3. 3

    Base layer (stone dust at 100 lb/ft³)

    20 × 100 ÷ 2,000 × 1.10 = 1.1 tons

  4. 4

    As bags (pea only)

    20 × 1.10 ÷ 0.5 = 44 bags

Result: About 1 ton of pea gravel + 1.1 tons of stone dust base — or 44 bags if delivery isn't practical.

Bulk vs bags: the real math

Pea gravel questions

How much pea gravel do I need for a 12×12 patio?
At the typical 3-inch depth: 144 ft² × 0.25 ft = 36 ft³ = 1.33 yd³ ≈ 1.7 tons, or about 79 half-cubic-foot bags. That bag count is the argument for bulk delivery — at $5 a bag it's $395 versus roughly $90 of bulk stone plus delivery.
How many bags of pea gravel in a ton?
A ton of pea gravel is about 20.8 ft³, so roughly 42 standard 0.5 ft³ bags. Above 15–20 bags, bulk delivery is nearly always cheaper — see the pea gravel cost guide for the crossover math.
How deep should pea gravel be?
2 inches for walkways over a compacted base, 3 for patios and seating areas, 4+ for loose-fill zones. Deeper isn't better for walking surfaces — past 3 inches the rounded stones shift underfoot like dry sand. Playground fall zones are the exception: CPSC guidance calls for 9 inches of loose fill.
Does pea gravel need a base layer?
For anything you walk on, yes: 2–3 inches of compacted crusher run or stone dust under the pea gravel stops it from pumping into the soil and halves long-term top-ups. Purely decorative beds can go straight over landscape fabric.
Why is my delivered pea gravel a different color?
Pea gravel is river-run natural stone, so color follows the local deposit — tan/brown in most regions, grayer where deposits are granitic. Ask your supplier for a photo of the current stockpile, and buy the whole job from one load to avoid a two-tone patio.

Everything pea gravel

What it is, sizes, cost, coverage, landscaping ideas and installation — the complete series.

Start with: What Is Pea Gravel?

The pea gravel series

What Is Pea Gravel?The smooth, rounded stone — and where it belongs.GuidePea Gravel Sizes1/4 to 5/8 inch grades and what each suits.GuidePea Gravel CostPer ton, per yard and per bag, priced honestly.GuidePea Gravel CoverageCoverage tables at every practical depth.GuidePea Gravel Landscaping GuidePaths, patios, xeriscapes and drainage done right.GuidePea Gravel Installation GuideBase, edging and depth — the 90-minute skill.GuidePea Gravel FAQMigration, weeds, dogs and other realities.FAQ

Other gravel tools

Gravel CalculatorCrushed Stone CalculatorGravel Cost Calculator

Sources & references

  1. [1]ASTM C29/C29M: Bulk Density (Unit Weight) and Voids in Aggregate — ASTM International, 2017
  2. [2]The Aggregates Handbook, 2nd ed. — National Stone, Sand & Gravel Association, 2013