Landscaping & Yard

Gravel Calculator

Enter the size of your area, the depth and the type of stone. You get cubic yards, a planning weight range in tons based on government conversion factors, the number of bags, and whether bulk delivery or bags cost less. For a compacted base layer, it adds the published allowance for compaction.

Free, no sign-upFormulas & sources shownReviewed Oct 9, 2026
Area shape
ft
ft
in
The depth above is
Finished depth adds a sourced loose allowance: ×1.33 for dense-graded base (FHWA). For pea gravel the only published figure is CPSC’s playground surfacing (12 in installed per 9 in compressed), so use Finished only for a playground.
cu ft
QUIKRETE bagged rock is 0.5 cu ft; check the volume printed on your bag
Weight, extra & prices
%
Optional rule of thumb, not a standard
t/yd³
Weight per loose yard; replaces the planning range
Bulk is priced per
$
Per ton or per yd³, as selected
$
$/bag
For the bag size above
20 ft 10 ft 3 in deep (thickness enlarged)3 t = 1.85-2.34 yd³ delivered(pile height exaggerated)
Pea gravel needed1.85 yd³50 cu ft loose over 200 sq ft
Est. weight
2.4-3 tons
Order by weight (high estimate)
3 tons
0.5 cu ft bags
100
Bulk, 3 t delivered
$235
Bagged
$600
Bulk delivery (3 t) saves about $365 over 100 bags. Have it dumped close to where you will spread it, on a tarp or a hard surface.
Paths and beds: we found no published depth. Playgrounds: CPSC’s public-playground handbook (2025, Table 2) lists pea gravel at 12 in installed / 9 in compressed as protecting only to a 5 ft fall height, for when impact-tested surfacing is not available. For a swing, the fall height is the height of the pivot point (where the swing hangs from the beam). For anything higher, use a material rated for that height or surfacing tested to ASTM F1292. To size that playground layer, choose “Finished (compacted / settled)” and enter 9.
Shopping list
  • 3 tons of pea gravel (≈ 1.85-2.34 yd³; you need 1.85 yd³; rounded up to ½ t)
  • Landscape fabric under the stone (optional, cut to the area plus overlaps)
  • Wheelbarrow, square shovel and a hard rake

1.85 yd³ of loose pea gravel weighs about 2.4-3 t at 1.28-1.62 t/yd³ (2.5 t at 1.35). These are representative planning weights from different materials and moisture conditions, not limits for your stone, so the ton order uses the high value. Ask your supplier for their weight per loose yard before you order by weight.

How to use this calculator

  1. Pick the shape and enter the size in feet. Split irregular areas into rectangles and add the results.
  2. Enter the depth in inches and choose the material. The volume is the same for every stone, but the weight per yard is not.
  3. Say which depth you entered if you’re spreading dense-graded base, or pea gravel under playground equipment. Finished (compacted / settled) adds the compaction allowance described below.
  4. Enter the bag size and your prices under Weight, extra & prices, per ton or per cubic yard as your quote reads. The defaults are placeholders. If your supplier tells you what a loose yard of their stone weighs, enter it to replace the planning range.

The formula

Volume (cu ft) = length (ft) × width (ft) × depth (in) ÷ 12

Cubic yards = cubic feet ÷ 27

Tons = cubic yards × tons per cubic yard

For a round area, the area is π × radius². One cubic yard covers 324 sq ft at 1 inch, 162 sq ft at 2 inches, 108 sq ft at 3 inches, 81 sq ft at 4 inches and 54 sq ft at 6 inches.

Bags are cubic feet ÷ bag size, rounded up. Bulk is rounded up to the next half ton or half yard. That’s a rule of thumb, so ask how your supplier sells. The cost comparison and shopping list use the same rounded numbers.

Tons to order = needed yards × the high planning weight per yard, or your supplier’s figure. Heavier or wetter stone gives you less volume per ton, so ordering on the high value keeps you from running short.

How much does a cubic yard of gravel weigh?

Material Planning tons per loose cubic yard (low - typical - high) Where the numbers come from
Pea gravel, river rock 1.28 - 1.35 - 1.62 Low: loose gravel 2,565 lb/yd³. Typical: dry gravel 100 lb/ft³ = 2,700 lb/yd³. High: wet gravel up to 120 lb/ft³ (all from the U.S. EPA table, 2006). LA County (2,632.5 lb) and New Mexico EMNRD (1.42 t) fall inside this range. No source lists pea gravel or river rock separately
Crushed stone (#57) 1.15 - 1.35 - 1.47 Low: crushed limestone 85 lb/ft³. Typical: crushed stone 100 lb/ft³ (both EPA table). High: 108.7 lb/ft³, the vibrated maximum of a No. 57 diabase (FHWA-HRT-15-034)
Crusher run / dense-graded base 1.25 - 1.40 - 1.62 Low: base course 1.25 t/yd³ (New Mexico EMNRD). Typical: 1.4 t per loose yard for aggregate with a specific gravity of about 2.70 (FHWA WFL Estimating Handbook, §301). High: Penn State’s DSA order factor, 0.04 t per sq ft for an 8 in loose lift = 1.62 t/yd³

These are representative planning values from different materials and moisture levels, not limits for one product. The 108.7 lb/ft³ is a lab maximum for a single sample. Order by your supplier’s weight per loose yard.

Compacted base weighs more per yard once it’s in place. Wisconsin DOT uses 1.85 t/yd³, and the FHWA handbook’s factors work out to 1.33 × 1.4 × 1.06 ≈ 1.97. So the calculator first turns a compacted depth into a loose volume, then weighs that loose volume.

How much extra for compaction?

Only two materials get a compaction allowance, because only those have a published basis:

  • Dense-graded base (crusher run): loose volume = compacted volume × 1.33, from the FHWA Western Federal Lands Estimating Handbook (Dec. 2025, §301). Penn State’s DSA Handbook says the same thing in inches: 8 in loose compacts to 6 in, and 6 in to 4½ in.
  • Pea gravel as playground surfacing only: the CPSC Public Playground Safety Handbook (July 2025) says loose fill “will compress at least 25% over time,” and its Table 2 lists pea gravel at 12 inches installed for 9 inches compressed. We found no figure for paths or beds, so for those, enter the depth as spread.

We found no published allowance for #57 stone or river rock, so none is applied. Extra for uneven ground is an optional rule of thumb (default 0%).

Worked example: a 20 × 10 ft pea gravel area

  • Volume: 20 × 10 × 3 ÷ 12 = 50 cubic feet = 1.85 cubic yards
  • Weight: 1.85 × 1.28-1.62 = about 2.4-3.0 tons (2.5 tons at the typical 1.35 t/yd³). Order 3 tons unless your supplier gives you their weight per yard
  • 3 tons buys about 1.85 yd³ of the heaviest stone and about 2.34 yd³ of the lightest, so never less than you need
  • In 0.5 cu ft bags: 50 ÷ 0.5 = 100 bags

At the placeholder prices ($45 per ton plus $100 delivery, $6 per bag), bulk costs $235 and bags cost $600.

Worked example: a compacted base for a 12 × 10 ft patio

Oregon State University Extension’s paver guide gives a 4-6 inch crushed-rock base for a patio, more on soft clay or where you will drive on it. For 4 inches compacted:

  • Compacted volume: 12 × 10 × 4 ÷ 12 = 40 cu ft
  • Loose volume to buy: 40 × 1.33 = 53.2 cu ft = 1.97 yd³
  • Weight: 2.46-3.19 tons (2.76 tons at 1.4 t/yd³), so order 3.5 tons

OSU suggests spreading the base in about three layers and compacting each one with a plate compactor.

How thick should a gravel driveway be?

There is no single number. Your town or county may have its own driveway standard, so ask your road or building department before you order. Here is what the published guides say:

  • The FHWA’s Gravel Roads Construction & Maintenance Guide (2015) sizes the gravel layer by subgrade support and the number of heavy trucks a day. It says it is good to get engineering advice if at all possible.
  • Its Table 3 suggests minimum gravel layers for new or rebuilt rural roads with 0-5 heavy trucks a day: 6.5 in on low subgrade support, 5.5 in on medium and 4.5 in on high. It also says to place gravel in separate layers when the total will exceed 4 inches.
  • Penn State places its road surface aggregate in one 6-8 inch loose lift, compacted to 4½-6 inches with a 10-ton vibratory roller, and wants at least 12 inches of stone over separation fabric.
  • Wisconsin DOT limits each compacted base layer to 6 inches with a pneumatic roller or 8 inches with a vibratory roller. With a rented plate compactor, follow its manual instead.

For example, a 10 × 50 ft drive with 6 in of compacted base needs 250 cu ft × 1.33 = 332.5 cu ft (12.31 yd³ loose). That’s about 15.4-20 tons (17.24 t at 1.4 t/yd³), so order 20 t on the high value.

Tips

  • Ask for the supplier’s weight per yard. It’s the only number that reflects their stone and its moisture.
  • Know your stone. QUIKRETE All-Purpose Gravel has an approximate top size of 3/8 in and meets ASTM C33 for concrete aggregate. No. 57 stone is a narrowly graded stone with few fines (very fine, dust-sized particles), and the FHWA tested it among its open-graded aggregates (FHWA-HRT-15-034). OSU Extension notes that the mixed sizes and sharp edges of crushed rock make it easy to compact.
  • Playgrounds: the CPSC’s public-playground handbook rates 9 inches of compressed pea gravel only to a 5 ft fall height, for use when impact-tested surfacing is not available. On a swing, the fall height is the height of the pivot point on the beam, not the seat. For anything higher, use a material rated for that height or surfacing tested to ASTM F1292. The handbook is written for public playgrounds.
  • Next to a new slab or lawn? Work out the concrete with our concrete slab calculator and the soil with the topsoil calculator, so the finished grades line up.

Frequently asked questions

How many tons is a cubic yard of gravel?

Roughly 1.3 to 1.6 tons for loose gravel. The U.S. EPA's conversion table lists loose gravel at 2,565 lb (1.28 tons) per cubic yard, dry gravel at 100 lb per cubic foot (2,700 lb or 1.35 tons per yard) and wet gravel at up to 120 lb per cubic foot (1.62 tons). Crushed stone runs from about 1.15 tons per yard (crushed limestone, 85 lb/ft³) to about 1.47 tons, and dense-graded base from 1.25 to about 1.62 tons per loose yard. These are planning values from different materials and moisture levels, not limits for any one product, so ask your supplier what their material weighs per loose yard before you order by weight.

How much gravel do I need for a 20 × 10 ft area?

At 3 inches deep you need 1.85 cubic yards: about 2.4 to 3.0 tons of pea gravel, or 100 bags of 0.5 cu ft. The math is 200 sq ft × 0.25 ft = 50 cubic feet, which is 2.5 tons at 1.35 tons per yard. Unless your supplier tells you their weight per yard, order 3 tons: 2.5 tons of heavier, wetter stone would cover only about 2.5 inches.

How many bags of gravel make a cubic yard?

54 bags of 0.5 cu ft, because a cubic yard is 27 cubic feet. That's the size of QUIKRETE's bagged rock varieties such as Pea Pebbles, River Pebbles and Crushed Rock. Some gravel is sold by weight instead: QUIKRETE All-Purpose Gravel comes in 50 lb bags with no volume on the data sheet. At the EPA's 100 lb per cubic foot for dry gravel, a 50 lb bag would be about 0.5 cu ft, but that is our estimate.

How much pea gravel do I need for a path?

Multiply length × width × depth in feet. A 10 × 4 ft path 2 inches deep needs 6.67 cubic feet, or 14 bags of 0.5 cu ft (13.3, rounded up). We found no extension or manufacturer guidance on path depth, so choose the depth you want and check the coverage printed on the bag.

How much gravel do I need for a driveway?

It depends on your soil, drainage, climate and how often heavy trucks use the drive, so there is no single answer. As a reference, the FHWA's Gravel Roads Construction & Maintenance Guide (2015) suggests a minimum of 4.5 to 6.5 inches of gravel for new rural roads with up to 5 heavy trucks a day, depending on how well the subgrade supports loads. More heavy trucks call for a thicker layer. Check your town or county driveway standard, or ask a local contractor or engineer. Once you know the compacted thickness, choose dense-graded base and select Finished, and the calculator adds the FHWA's 1.33 factor for loose material.

How much extra gravel do I need for compaction?

For dense-graded base, multiply the compacted volume by 1.33 to get the loose volume to buy. That's the factor in the Federal Highway Administration's Western Federal Lands estimating handbook, and Penn State's Driving Surface Aggregate handbook likewise places 8 inches loose to get 6 inches compacted. For pea gravel used as public-playground surfacing, the CPSC says loose fill compresses at least 25% over time, and its table lists 12 inches installed for 9 inches compressed. That's the only published figure for pea gravel. We found no published allowance for clean #57 stone or river rock, so the calculator applies none. Add your own extra percentage if you want a margin.

Sources

Last reviewed Oct 9, 2026. See how we calculate. Results are planning estimates - confirm with your supplier and local code.