Enter your area and depth to get tonnage, volume, bag counts and truckloads — and choose loose or compacted, because the same gravel weighs 40% more once it is rolled.
Gravel is really a family of products, and that is the first thing most calculators get wrong. Graded crushed stone with fines compacts into a firm base. Single-size clean stone — pea gravel, river rock, 3/4 inch clean — does not. They are ordered by weight, but their densities differ, so a single 'gravel density' is a fiction.
This calculator covers the graded, compactable products, and it makes you choose the placement state, because that is the variation that actually matters: AASHTO gives 100 lb/ft³ for loose aggregate and about 140.7 lb/ft³ once it has been rolled — roughly a 40% difference. Most calculators pick one number and never tell you which.
The density figures come from AASHTO's LRFD unit weight table, which we retrieved in full, and from state DOT estimating manuals. We link every source and quote the line it came from.
A worked example you can check by hand
A 20 ft × 10 ft area at 2 in deep,
with a 5% waste allowance:
Area
200 ft² (20 ft × 10 ft)
Depth
2 in = 0.1667 ft
Volume (before waste)
33.3333 ft³
Waste allowance
5%
Volume (with waste)
35 ft³ = 1.2963 yd³
Density used
100 / 100 / 100 lb/ft³ (low / typical / high)
Weight (low)
3,500 lb = 1.75 short tons
Weight (typical)
3,500 lb = 1.75 short tons
Weight (high)
3,500 lb = 1.75 short tons
How we calculate this — and every number we used
We do not use a hidden "magic number". Here is the entire calculation:
volume = area × depth
volume_with_waste = volume × (1 + waste%)
weight = volume_with_waste × density
Why a range, not one number? Bulk material density changes with
moisture, gradation and compaction. Publishing a single figure would be falsely precise, so we publish
the range our sources support — and we show you exactly where each number comes from.
Why you can pick the state. The same material weighs very different
amounts loose, in place, or compacted — WisDOT measured volume changes of 27–60% on compaction alone.
Most calculators hide this behind one number. We let you choose.
Gravel / crushed stone — loose (tipped, uncompacted)
How we chose the typical value. AASHTO LRFD Table 3.5.1-1 gives 0.100 kcf (= 100 lb/ft³ = 1.35 short ton/yd³) for 'Loose Sand, Silt or Gravel'. Loose sand and loose gravel share this row by the standard's own convention.
Single-source constant. We could only retrieve one authoritative
published figure for this material, so the range may understate real-world variation.
Confirm the figure with your supplier before ordering.
Limits of this constant
AASHTO publishes these as 'traditional unit weights' and states in C3.5.1 that the unit weight of granular materials depends on the degree of compaction and water content. They are design nominal values, not measured statistics.
IMPORTANT: this row is for loose aggregate generally. Single-size decorative stone — pea gravel, river rock, 3/4 inch clean stone — has more void space and we found NO authoritative density for those products. This calculator does not cover them.
Once rolled or compacted, graded gravel reaches about 140 lb/ft³ — switch the state selector.
How we chose the typical value. AASHTO LRFD Table 3.5.1-1 gives 0.140 kcf (140 lb/ft³) for 'Rolled Gravel, Macadam or Ballast'. Iowa DOT independently gives 140 pcf for Class 'A' crushed stone. Two independent authorities land on the same figure, which is why the typical value is 140.7 lb/ft³ (1.90 short ton/yd³) and the band comes from WisDOT's research-measured 1.78–1.98 t/yd³.
Limits of this constant
AASHTO publishes these as 'traditional unit weights' and states in C3.5.1 that the unit weight of granular materials depends on the degree of compaction and water content. They are design nominal values, not measured statistics.
This is graded, compactable aggregate. Single-size clean stone (pea gravel, river rock, #57) compacts poorly and is NOT covered by this figure.
Compacted in-place density. Loose delivered volume is much larger — see the state selector.
This calculator is only valid under these assumptions. If any of them do not match your project,
treat the result as a rough guide and get a quote from your supplier.
The area is treated as a rectangle. Split irregular shapes into rectangles and add them.
Depth is the COMPACTED thickness for a base layer, or the loose spread depth for decorative gravel.
The material is graded aggregate — crushed stone with fines, or ballast that compacts. It is NOT single-size decorative stone.
You are buying aggregate by weight and placing it in one layer. Deep fills should be placed and compacted in lifts.
The density values are AASHTO design unit weights, which the standard itself describes as traditional values that depend on compaction and water content.
Frequently asked questions
How many tons of gravel do I need?
Multiply your area by the depth to get volume, then multiply by density. At 3 inches deep, one square foot of loose gravel weighs about 25 lb and compacted gravel about 35 lb, so 400 square feet needs roughly 4.5 short tons loose or 6.3 short tons compacted. Use the state selector to match your situation.
How much does a cubic yard of gravel weigh?
About 1.35 short tons per cubic yard loose, and about 1.9 short tons per cubic yard once rolled and compacted. The difference is not measurement error — it is the same material with the voids squeezed out.
Does this work for pea gravel or river rock?
No, and we would rather say so than give you a wrong number. AASHTO publishes no density for single-size decorative stone, and we could not find an authoritative figure elsewhere. Pea gravel and river rock also have far more void space, so their bulk density is lower and less predictable. Use this calculator for the volume, then ask your supplier for the density of the exact product.
Should I measure the gravel loose or compacted?
Order compacted if you are building a base — the supplier's tonnage is what gets compacted in place. If you are spreading decorative gravel and will not compact it, use the loose figure. When in doubt, ask for the supplier's own density.
Why is AASHTO's figure lower than some websites?
AASHTO gives 140.7 lb/ft³ for rolled gravel as a structural design value, while some aggregate suppliers quote about 1.4 to 1.5 short tons per cubic yard for loose product. Those are not contradictory — they describe different states. We show both ends and let you pick.