Pea Gravel Calculator — Bags, Yards, Tons & Cost

How to Calculate Pea Gravel for Pathways, Patios & Drainage

Pea gravel is one of the few landscape materials where ordering the right quantity is only half the problem — the other half is whether it stays where you put it. Because pea gravel is small (approximately ⅜ in) and naturally rounded, it rolls under foot traffic and migrates downslope over a single season. A project that calculates correctly to 2 inches deep but skips proper edging or underestimates slope effect will need a top-up every year. The real planning challenge with pea gravel is not just volume — it is choosing the right depth for the application so the stone provides adequate cover without becoming a maintenance problem.

This calculator is the dedicated tool for decorative landscape pea gravel applications — paths, patios, drainage beds, and garden borders — and is differentiated from the general gravel calculator, which teaches the density model for any stone type. Enter your area dimensions and desired depth, and the calculator returns loose volume in cubic yards and cubic feet, weight in tons and pounds, number of standard 50 lb bags, an area-based coverage rate in square feet per ton, and an optional material cost from a price per ton or per bag.

Key Features of the Pea Gravel Calculator

Three Application Depth Presets

One-click presets for 2 in decorative cover, 3 in weed-control over landscape fabric, and 4 in drainage bed — each loads the depth most appropriate for that use case.

Coverage Rate in sq ft per Ton

Returns how many square feet one ton of pea gravel covers at the entered depth — matches the coverage figures on bulk supplier invoices so you can cross-check the order before delivery.

Standard 50 lb Bag Count

Converts the adjusted volume directly to the number of standard 50 lb / 0.5 cu ft bags sold at home improvement stores — useful for smaller garden beds where bulk delivery is impractical.

Migration Depth Advisory

Flags when the selected depth falls below 2 inches, where rounded pea gravel rolls loose under foot traffic and exposes bare soil within one season of use.

Slope & Angle-of-Repose Warning

Alerts when project conditions suggest use on slopes steeper than 5–8°, where pea gravel's low angle of repose causes progressive migration — recommends edging or switching to angular stone.

Adjustable Waste / Migration Factor

Default waste of 10% covers raking loss on flat, edged ground; raise to 15–20% for slopes or open-edge beds where pea gravel rolls to the low side between seasons.

Landscape Fabric Recommendation Note

Results panel flags whether landscape fabric is recommended based on depth — bare soil without fabric at 3 in or less allows pea gravel to sink and weeds to push through.

Dual-Mode Pricing

Enter a price per ton for bulk supply yard orders or per bag for hardware-store purchases — the calculator prices the project on whichever unit you provide.

Metric and Imperial Outputs

Returns volume in yd³, ft³, and m³ and weight in tons, lb, and kg — covers both US landscape contractors and metric garden designers in one pass.

Four Project Shape Options

Handles rectangular beds and pathways, circular fire-pit surrounds, triangular corner fills, and circular ring areas — footprint math switches without any manual conversion.

Print / Save Estimate as PDF

One click opens a clean, branded summary of all inputs and results — bring it to the supply yard or share it with a landscaping crew for quoting purposes.

Cross-Links to Related Gravel Tools

Results panel links to the general gravel calculator for cross-material density comparisons and to the gravel cost calculator for full delivery and labor budgets.

How to Use the Pea Gravel Calculator

1
Select your project type using the preset buttons — Decorative Path, Weed-Control Bed, Drainage Bed, or Play Area. Each preset loads the recommended depth and waste factor for that application.
2
Choose your measurement unit (in, ft, cm, or m) and enter the footprint dimensions: Length and Width for rectangular paths and beds, Radius for circular areas, or Base and Height for triangular corner fills.
3
Review the auto-loaded depth or adjust it manually. Standard guidance: 2 in for light decorative cover on flat, edged surfaces; 3 in for weed suppression over landscape fabric; 4 in for drainage beds or play areas; 2 in minimum for any regularly walked surface.
4
Set the Waste factor. Leave it at 10% for flat-ground projects with solid edging. Increase to 15–20% for sloped areas or open-edge borders where pea gravel migrates between seasons.
5
Check the migration advisory in the results: if your selected depth is below 2 in, the panel will flag that pea gravel at this depth rolls loose under foot traffic. Increase the depth or plan for solid edging before finalizing the order.
6
Enter your pea gravel price: per ton for bulk supply yard orders (typical US range: $25–$75/ton) or per bag for hardware-store purchases (typical: $4–$8 per 50 lb bag). The calculator prices the project on whichever unit you provide.
7
Press Calculate. The results panel shows volume in cubic yards, cubic feet, and cubic meters; weight in tons, pounds, and kilograms; number of 50 lb bags; coverage in square feet per ton; and estimated material cost.
8
Cross-check the coverage rate in the results against the coverage figure your supplier advertises. If the numbers differ, the supplier is using a different depth assumption — adjust your depth input until the coverage figures match.
9
For L-shaped or irregular garden beds, measure each rectangular section separately, run the calculator for each, and add the cubic-yard totals. The tonnage and bag counts add directly without any further conversion.
10
Click Print / Save to generate a PDF summary of all inputs and results. Bring it to the supply yard or share it with a landscaping contractor for quoting.

Formulas Used in the Pea Gravel Calculator

1) Footprint AreaRectangle: Area = Length × Width | Circle: Area = π × Radius² | Triangle: Area = (Base × Height) ÷ 2
All dimensions are converted to feet before the area is computed, so a footprint measured in inches or centimeters resolves to a single square-foot value without manual conversion.
2) Loose VolumeVolume (ft³) = Area (ft²) × Depth (ft) | Volume (yd³) = Volume (ft³) ÷ 27
The cubic-yard figure is what a bulk supplier loads against. Dividing by 27 converts cubic feet to cubic yards (there are exactly 27 cubic feet in one cubic yard).
3) Waste / Settling AdjustmentAdjusted Volume = Loose Volume × (1 + Waste% ÷ 100)
Accounts for pea gravel spillage at edges, slight settling under foot traffic, and minor volume lost when freshly delivered loose stone is spread and walked in. Applied before weight, bag count, and cost are computed.
4) Weight From DensityWeight (lb) = Adjusted Volume (ft³) × 100 lb/ft³ | Weight (tons) = Weight (lb) ÷ 2000
Pea gravel (⅜ in, rounded, dry) is approximately 100 lb/ft³ (1,600 kg/m³) based on ASTM C33/C33M grading data. This is lighter than general all-purpose gravel (~105 lb/ft³) and significantly lighter than dense-graded crusher-run (~120 lb/ft³). One cubic yard of pea gravel weighs roughly 2,700 lb (1.35 tons).
5) Coverage Ratesq ft per Ton = (2,000 ÷ Density lb/ft³) ÷ Depth (ft)
At 100 lb/ft³ and 3 in (0.25 ft) depth, one ton covers ≈ 80 sq ft. This is the figure to compare against the supplier's quoted coverage when confirming an order. If the numbers differ, both parties are assuming different depths.
6) Bag CountBags = Adjusted Volume (ft³) ÷ 0.5 (standard 50 lb / 0.5 cu ft bag)
Standard bags at major home improvement stores contain 0.5 cubic feet of pea gravel at approximately 50 lb each. It takes 54 bags to fill one cubic yard. Smaller 25 lb (≈ 0.25 cu ft) bags are also sold — use the bag-size selector to switch.

Worked Example: A 6 ft × 30 ft Garden Pathway at 3 Inches

You are finishing a 6 ft wide, 30 ft long walking path between two garden beds with pea gravel at a 3 in weed-control depth over landscape fabric. Start with the footprint: 6 ft × 30 ft = 180 sq ft. Convert depth to feet — 3 in ÷ 12 = 0.25 ft — and multiply: 180 ft² × 0.25 ft = 45 ft³, or 45 ÷ 27 = 1.67 yd³ loose. Apply the 10% waste factor for a flat, edged path: 45 × 1.10 = 49.5 ft³ (1.83 yd³ adjusted). Convert to weight: 49.5 ft³ × 100 lb/ft³ = 4,950 lb ÷ 2,000 = 2.48 tons. At a typical bulk price of $45 per ton, the material cost is 2.48 × $45 = $111.60. If buying at a hardware store, you need 49.5 ÷ 0.5 = 99 standard 50 lb bags. One ton covers 80 sq ft at 3 in, so you need 180 ÷ 80 = 2.25 tons before waste — matching the 2.48 tons with waste. Had you estimated at 2 in instead of 3 in, you would have ordered only 1.22 yd³, which leaves weed seeds a viable gap to the soil below even over landscape fabric within one growing season.

Pea Gravel Coverage Table — sq ft per Ton by Depth

The table below shows how many square feet one ton of pea gravel covers at each standard depth, the equivalent cubic yards per ton, the number of 50 lb bags needed per 100 sq ft, and the recommended application. Use it to cross-check your order against the coverage figure a supplier advertises — if their number differs from the table, they are quoting at a different depth assumption than you entered.

Depth	sq ft / Ton	yd³ / Ton	50 lb Bags / 100 sq ft	Typical Application
1.5 in	~160	0.09	~25	Light accent; flat, edged only — not walked
2 in	~120	0.12	~33	Decorative ground cover, flat garden beds with edging
3 in	~80	0.19	~50	Weed suppression over landscape fabric; standard pathway
4 in	~60	0.25	~67	Drainage bed, dry creek, or play area surfacing
6 in	~40	0.37	~100	Deep drainage layer; French drain pipe bedding

Based on dry pea gravel at 100 lb/ft³ (ASTM C33 grading). Add 10–20% for waste and migration. Damp pea gravel weighs 5–10% more per ton, reducing actual coverage per ton slightly.

Migration, Slope & Edging Factors

Pea gravel's rounded shape gives it a natural angle of repose of roughly 25–30°, which sounds steep — but in practice any visible grade causes it to migrate toward the low edge of a bed over time. A path that slopes just 5° (a rise of about 1 in per foot of run) will see pea gravel creeping toward the downhill side after a few rain events. For any sloped surface: install solid edging (aluminum, steel, or concrete curb restraint) at least 3 in tall; increase the order by 15–20% for an annual top-up allowance; and consider switching to angular crushed stone (ASTM D448 Size #57) that locks together rather than rolling. The general gravel calculator lets you compare densities and tonnage across stone types if you are weighing pea gravel against a coarser angular alternative. For drainage channels where stone movement is planned by design, the gravel cost calculator includes material, delivery, and periodic re-grading labor in the full project budget.

Common Pea Gravel Estimating Mistakes

Ordering at 2 in for a weed-control bed without landscape fabric. Two inches is just enough to cover bare soil visually, but exposed soil at this depth lets weeds push through within one growing season — pea gravel does not compact into a sealed layer the way mulch does. The correct depth over bare soil for weed suppression is 4 in; over landscape fabric, 3 in is sufficient. This one mistake generates most pea gravel re-order calls within the first season.
Comparing a new pea gravel order to a previous crushed-stone order by tonnage. Pea gravel runs ~100 lb/ft³; crusher-run runs ~120 lb/ft³. If your last order was 3 tons of crusher-run and you order 3 tons of pea gravel, you receive about 20% more volume than you expect — potentially overfilling a bed. When switching stone types, always compare by cubic yards (volume), not by tonnage, and use the gravel tons-to-yards calculator to reconcile supplier quotes across materials.
Not adding extra for slope migration. The calculator returns the nominal volume for a flat, fully contained area. On any slope or open-edge bed, pea gravel migrates to the low side over the first season. A 10% waste factor is appropriate for flat, edged surfaces; raise it to 15–20% for any visible grade or open-edge border. Skipping this means an annual top-up that could have been built into the original order at a lower cost.
Buying in bags for projects over 2 cubic yards. At 54 bags per cubic yard, a 3 yd³ project requires 162 standard 50 lb bags at $4–8 each — $650–$1,300 total. The same volume in bulk from a supply yard typically costs $135–$270 at $45–$90 per yard, plus a delivery charge of $50–$200. For any project larger than about 2 cubic yards, calling a local supply yard almost always yields significant savings over the per-bag price at a home improvement store.

When to Use This vs. a Related Calculator

Use this calculator when the stone is pea gravel (approximately ⅜ in, rounded) and the application is decorative or drainage — paths, patios, borders, dry creeks, or play areas. For multi-material comparisons or projects where you have not yet decided on stone type, the general gravel calculator lets you switch between material densities and see how tonnage changes across stone types. If the primary question is total budget including delivery and spreading labor, use the gravel cost calculator. For a layered driveway build-up with sub-base, base, and surface courses — a project that almost always uses angular crushed stone rather than pea gravel — use the gravel driveway calculator, which handles per-layer compaction factors. If a supplier has quoted you a tonnage and you need to verify the cubic-yard volume you are actually receiving, the gravel tons-to-yards calculator converts between the two at pea gravel's density.

Standards & References

ASTM D448

Standard Classification for Sizes of Aggregate for Road and Bridge Construction

Defines the sieve-size classification numbers that suppliers use to name aggregates. Pea gravel sold in the US typically falls within Size #8 (approximately ⅜ in) or Size #89 (¼ in to ½ in). Knowing the size class lets you match the density preset in this calculator to the specific material your supplier carries and verify the coverage figures before ordering.

ASTM C33/C33M

Standard Specification for Concrete Aggregates

Provides grading and quality requirements for fine and coarse aggregates. The ~100 lb/ft³ (1,600 kg/m³) bulk density used in this calculator to convert pea gravel volume to weight is based on ASTM C33-compliant well-graded fine aggregate data. This is why the calculator's tonnage figure matches what a compliant supplier's scale house returns for the same volume.

ASTM F1292

Standard Specification for Impact Attenuation of Surfacing Materials Within the Use Zone of Playground Equipment

Governs loose-fill surfacing materials — including pea gravel — used under playground equipment. The standard specifies minimum uncompressed depths for fall protection by equipment height: typically 9 in for equipment up to 6 ft and up to 12 in for equipment up to 10 ft. The 4 in play-area depth preset in this calculator is a layout-and-ordering starting point; always verify the required depth against ASTM F1292 for the specific equipment height before ordering for a playground installation.

Density values are typical dry, loose figures for pea gravel; actual weight varies with moisture content and stone source. Confirm the lb/ft³ specification with your supplier before ordering for structural fill, drainage, or playground applications where depth compliance is required.

Frequently Asked Questions

What is pea gravel and what is it used for?

Pea gravel is a naturally rounded, smooth stone approximately ⅜ inch in diameter, typically washed to remove fines. Its pebble-like appearance and soft texture underfoot make it popular for decorative garden paths, patios, borders, and fire pit surrounds. It is also widely used as a drainage aggregate in French drains, pipe bedding, and dry creek beds because the rounded stones pack loosely and allow water to flow freely. Unlike crushed stone, which locks together angularly under load, pea gravel does not compact hard — which makes it comfortable underfoot but prone to rolling and migration on slopes.

How much pea gravel do I need for a 10 × 10 ft area?

For a 10 × 10 ft area at 3 in depth (the standard weed-suppression depth over landscape fabric): the volume is 100 ft² × 0.25 ft = 25 ft³ ÷ 27 = 0.93 yd³ loose. Adding the default 10% waste brings it to roughly 1.02 yd³ and 1.38 tons. At 3 in, one ton covers approximately 80 sq ft, so the 100 sq ft area needs just over 1.25 tons before waste. If buying standard 50 lb bags, you need about 55 bags. At 2 in depth the same area needs only 0.68 yd³ and 0.92 tons — but that is only appropriate for flat, edged beds without weed concerns.

How deep should pea gravel be for a garden pathway?

For a garden path that will be walked regularly, 2 to 3 inches is the standard range. At 2 in, the stone feels firm underfoot on flat ground but may shift slightly and can expose bare soil within a season on any grade. At 3 in over landscape fabric the path feels more stable and the fabric prevents the gravel from sinking into the soil over time. Most landscapers recommend 3 in as the practical minimum for any walked surface, especially where the path has any visible slope.

How deep should pea gravel be for weed suppression?

Three inches over landscape fabric is the standard recommendation for effective weed suppression. Without fabric, no depth of pea gravel reliably suppresses weeds because the rounded stones do not form a sealed layer — weeds push through soil gaps regardless of depth. With landscape fabric, 2 in is technically sufficient to cover the fabric, but 3 in provides a more stable layer that resists wind displacement and looks more finished. Four inches is used in high-maintenance areas or wherever a thicker buffer is needed between the gravel surface and the fabric below.

How many square feet does a ton of pea gravel cover?

One ton of dry pea gravel (at approximately 100 lb/ft³) covers roughly 120 sq ft at 2 in depth, 80 sq ft at 3 in depth, and 60 sq ft at 4 in depth. These are the numbers to compare against a supplier's advertised coverage — if their figure differs, they are quoting at a different assumed depth. A ton of pea gravel contains about 20 cubic feet, so you can also estimate coverage directly: divide 20 by your depth in feet to get square feet per ton.

How many 50 lb bags of pea gravel do I need?

A standard 50 lb bag of pea gravel contains approximately 0.5 cubic feet of material. To find the number of bags, divide your adjusted cubic-foot volume by 0.5. For example, a 10 × 10 ft area at 3 in with 10% waste is about 27.5 ft³ ÷ 0.5 = 55 bags. As a rule of thumb, one cubic yard (27 cubic feet) requires 54 standard bags. For any project over 2 to 3 cubic yards, bulk delivery from a supply yard is almost always more cost-effective than buying individual bags.

Does pea gravel migrate or move over time?

Yes — pea gravel's rounded shape gives it a low angle of repose (roughly 25–30°), which means it rolls on even mild grades. On a flat, edged surface it stays fairly well-contained, but on any visible slope pea gravel will creep toward the low edge within one or two rain seasons. Managing migration requires solid edging (aluminum or steel at least 3 in tall, or concrete curbing), a minimum depth of 3 in so the layer stays functional after some rolling, and an annual top-up allowance of 10–20% of the original volume for sloped surfaces.

Can I use pea gravel on a slope or inclined surface?

Pea gravel is not ideal for slopes steeper than about 5 to 8 degrees (a rise of roughly 1 inch per foot of run). Above that grade, the rounded stones roll freely downhill under foot traffic and rain runoff. For sloped surfaces, angular crushed stone (ASTM D448 Size #57 or similar) is a better choice — the irregular faces interlock and hold a grade much better. If you proceed with pea gravel on a mild slope, install solid edging on the downhill side, increase the waste factor to 20%, and plan for an annual top-up to maintain full coverage depth.

Is pea gravel sold by the ton or by the yard?

Pea gravel is sold both ways. Bulk supply yards typically quote by the cubic yard (volume) or by the ton (weight), depending on regional convention and how their equipment measures the load. Home improvement stores sell it in bags by the cubic foot (50 lb ≈ 0.5 cu ft). When comparing quotes from different suppliers, always convert to the same unit: 1 cubic yard of pea gravel weighs approximately 2,700 lb (1.35 tons). Use the gravel tons-to-yards calculator to reconcile weight and volume quotes before placing an order.

How much does pea gravel cost?

Bulk pea gravel typically costs $25 to $75 per ton or $30 to $90 per cubic yard in the US, with wide regional variation based on stone availability and haul distance. Bagged pea gravel at home improvement stores runs $4 to $8 per 50 lb bag — roughly $160 to $320 per cubic yard, four to eight times the bulk price. Delivery charges of $50 to $200 per truckload are common for bulk orders, so smaller projects under about 2 cubic yards often cost less at a hardware store despite the higher per-unit price. For a full project budget including delivery, use the gravel cost calculator.

What is the difference between pea gravel and crushed stone?

Pea gravel is naturally rounded stone, typically ⅜ inch in diameter, tumbled smooth by water action. Crushed stone is mechanically broken angular rock (usually limestone or granite) graded by sieve size — a #57 stone runs roughly ¾ in to 1 in, for example. Angular crushed stone locks together under load and holds a slope; rounded pea gravel rolls freely and migrates. Use pea gravel for decorative surfaces, soft pathways, and open drainage where loose aggregate is appropriate. Use crushed stone for driveways, structural base courses, and compacted drainage where the stone must stay in place under load. The density difference is small (pea ~100 lb/ft³ vs. crushed ~100–105 lb/ft³), so the volume calculation is nearly identical — but the performance underfoot is very different.

Does pea gravel need landscape fabric underneath?

Yes, landscape fabric is strongly recommended under pea gravel in garden beds for two reasons: it prevents the pea gravel from sinking into the soil below over time (rounded stones work their way downward with each rain event), and it physically blocks weed seeds from contacting soil. Without fabric, both problems appear within 2–3 seasons — the gravel layer thins as stones sink, and weeds push through the gaps. Use a woven polypropylene fabric rated for gravel (not a fine-mesh fabric, which clogs with fines), overlap seams by 6 in, and staple the edges before laying gravel.

How do I calculate pea gravel for an irregularly shaped area?

Divide the area into simple geometric shapes — rectangles, circles, or triangles — and run the calculator separately for each section, using the same depth and waste factor throughout. Add the cubic-yard results together to get the total volume to order. For example, an L-shaped bed might be split into two rectangles: a 4 ft × 10 ft section and a 4 ft × 6 ft section, giving 40 ft² + 24 ft² = 64 ft² total. At 3 in depth that is 64 × 0.25 = 16 ft³ = 0.59 yd³ before waste, or about 0.65 yd³ with 10% added.

Is this pea gravel calculator free?

Yes, completely free. There is no sign-up, account, or paywall — enter your dimensions and press Calculate. The calculator runs entirely in your browser with no data sent to a server, so your project dimensions remain private. Results are available immediately after pressing Calculate.

Can I print or save my pea gravel estimate?

Yes. After pressing Calculate, the results panel shows a Print / Save button that opens a clean, branded print view in a new browser tab. In your browser's print dialog, choose Save as PDF to keep a digital copy. The print summary includes all your input dimensions, the volume in cubic yards and cubic feet, weight in tons and pounds, bag count, coverage rate in square feet per ton, and estimated material cost — everything you need to bring to a supply yard or share with a landscaping contractor.