Calculate Your Gravel Materials
Calculate cubic yards, tons, and 0.5-cu-ft bag counts for any rectangle, circle, or ring — with material-specific density, a compaction factor, and waste overage applied automatically.
Go to Gravel Calculator →Gravel is ordered two ways — by volume (cubic yards) and by weight (tons) — so you need both numbers before you call a supplier. Multiply length × width × depth (with depth in feet), divide by 27 for cubic yards, then multiply by the material's density (most crushed stone runs 1.4–1.5 tons per cubic yard) for tons. Then add a compaction factor — about 10% for clean stone, 20% for crusher run — because loose-delivered gravel shrinks when you pack it, plus 10% waste for spillage and edge loss. Skip the compaction step and you'll come up short on a driveway base.
Want the exact numbers without doing the arithmetic? The free Gravel Calculator returns cubic yards, tons, and 0.5-cu-ft bag counts for any rectangle, circle, or ring — with material-specific densities, a compaction toggle, and a waste factor built in. This guide explains the math behind it and the decisions it can't make for you: which gravel, how deep, and whether to order bags or bulk.
📐 The Two Numbers Every Supplier Asks For
Bulk suppliers in some regions price by the cubic yard (volume); quarries and DOT-spec yards often price by the ton (weight). Many will quote you in whichever unit you didn't bring, so calculate both. The volume math is identical for every material — only the weight conversion changes with density.
There are 27 cubic feet in a cubic yard, which is where the ÷ 27 comes from. Depth is almost always entered in inches, so it's divided by 12 to convert to feet first.
Worked example — a 50 × 12 ft driveway base, 4" deep:
- Volume = [50 × 12 × (4 ÷ 12)] ÷ 27 = [600 × 0.333] ÷ 27 = 7.4 cubic yards
- Weight = 7.4 × 1.5 t/yd³ = 11.1 tons (clean crushed stone)
- With a 1.20 crusher-run compaction factor: 7.4 × 1.20 = ~8.9 cubic yards to order
For round areas (a fire-pit border or tree ring) the calculator swaps in π × (diameter ÷ 2)² for the area, and for a ring it subtracts the inner circle. For an irregular yard, break it into rectangles and circles, run each, and add the volumes.
📏 How Deep? Recommended Depth by Use
Depth is the input people get most wrong, and it's the one that moves your order the most — doubling the depth doubles the tonnage. These are finished, compacted depths; add the compaction factor below to reach the loose-order quantity.
Compacted Depth by Application
| Use case | Depth (compacted) | Notes / source |
|---|---|---|
| Residential driveway (total build) | 8–12" in 2–3 layers | Sub-base + base + 2–3" top course |
| Paver base — walkway / patio | 4–6" | ICPI Tech Spec 2 (pedestrian) |
| Paver base — driveway (vehicular) | 6–8" | ICPI Tech Spec 2 (8–12" for streets) |
| Shed / outbuilding pad | 4–6" | #57 or crusher run on firm subgrade |
| French drain / drainage trench | ≥2" under pipe, ≥6" cover | Washed gravel per IRC R405.1 |
| Landscape ground cover | 2–3" | 2" minimum over fabric for weed suppression |
Soft subgrade pushes depth up
On soft, clay, or saturated soil, driveway base depths can climb to 14–18", and a geotextile separation fabric becomes essential so the stone doesn't pump down into the mud. In cold climates the base should also reach toward the local frost depth — which ranges from 0" in Florida to as much as 80"+ in Minnesota and North Dakota (FHWA frost-penetration data) — or include drainage so freeze-thaw doesn't heave the surface.
🪨 Which Gravel? Density Drives the Tonnage
"Most gravel weighs 1.4 to 1.7 tons per cubic yard" is the rule of thumb, but the spread is wider than that once you include lightweight and dense materials. A calculator that uses one generic density for everything will be wrong by 30%+ on lava rock or recycled concrete. These are bulk densities (loose to lightly settled, dry); moisture can add 5–10%.
Approximate Bulk Density by Material
| Material | Typical size | Tons / yd³ | Best for |
|---|---|---|---|
| #57 stone | ¾–1" | 1.2–1.4 | Drainage, driveway top, drain rock |
| #67 stone | ¾" to No. 4 | 1.2–1.3 | Concrete aggregate, drainage |
| Pea gravel | ⅛–⅝" rounded | 1.3–1.4 | Walkways, decorative beds, dog runs |
| Crusher run / DGA / ABC | ¾" minus to dust | 1.2–1.5 | Compactable base under everything |
| River rock | 1–3" rounded | 1.35–1.75 | Decorative, dry creek beds |
| Recycled concrete (RCA) | ¾" minus to 1½" | 1.15–1.4 | Budget base where DOT-approved |
| Lava rock (scoria) | ¾–2" | 0.55–0.70 | Lightweight mulch, fire features |
⚙️ The Compaction Factor Most Calculators Skip
This is the single biggest reason DIYers come up short. The depth you want is the finished, compacted depth — but gravel is delivered loose. When you tamp it, it shrinks, so you have to order more than the geometric volume. Most online calculators ignore this entirely.
Clean / open-graded stone
#57, #67, pea gravel, river rock settle only about 8%. Use a 1.10 multiplier on the compacted volume.
Dense-graded base
Crusher run, DGA, and RCA lose 15–25% loose-to-compacted. Use a 1.20 multiplier.
So a 7.4-yd³ compacted crusher-run base means ordering about 8.9 yd³ loose. For DOT-spec work the compaction target is even more demanding — TxDOT Item 247 flexible base requires 100% of maximum dry density, and ICPI paver bases want ≥98% Standard Proctor for residential. The calculator applies the right default by material and lets you override it.
➕ Waste & Overage
On top of compaction, add an overage for spillage, edge loss, settling, and the reality that suppliers round up to whole loads:
- +10% — standard rectangular project on firm subgrade. The widely cited default across the industry.
- +15% — irregular shapes, curves, or multiple obstacles where more material is lost to trimming and rework.
- +15–20% — sloped sites or soft / saturated / clay subgrade, where stone is lost into the subgrade and sheds off the slope.
Compaction and waste stack: a clean-stone bed gets ×1.10 (compaction) × 1.10 (waste); a crusher-run base on a soft slope can reach ×1.20 × 1.15 or more. Rounding up to the supplier's minimum load often absorbs the difference on small jobs.
🛍️ Bagged vs. Bulk: When to Switch
Home-center gravel comes in 0.5-cubic-foot bags (about 50 lb each). There are 54 of those bags in a cubic yard (27 ÷ 0.5). Coverage per bag depends entirely on depth:
| Depth | Coverage per 0.5 ft³ bag |
|---|---|
| 1" | 6.0 ft² |
| 2" | 3.0 ft² |
| 3" | 2.0 ft² |
| 4" | 1.5 ft² |
The crossover to bulk delivery is driven by labor and trips, not just unit price:
- Under ½ yard (~27 bags): bagged is practical — easy to haul and store.
- ½–2 yards (27–108 bags): borderline; depends on site access and the supplier's minimum load.
- Over 2 yards (108+ bags): order bulk. Hauling 100+ bags by hand isn't worth it, and a single dump-truck delivery eliminates dozens of trips.
❓ Quick Answers to Common Gravel Questions
What gravel size is best for a driveway?
A layered system: a coarse base (crusher run or 1–2" stone) for load-bearing, topped with a 2–3" surface course of #57 (¾–1") that locks together and sheds water. Avoid pure pea gravel as a driving surface — rounded stone migrates under tires.
How much gravel for a French drain?
Per IRC R405.1, set the perforated pipe on at least 2" of washed gravel and cover it with at least 6" more. A typical 10"-wide × 12"-deep trench needs roughly 0.7 ft³ of stone per linear foot — figure the trench as a rectangle and run it through the calculator.
Do I need landscape fabric under gravel?
Not strictly on firm, well-drained subgrade, but it's strongly recommended on clay or soft soil and is standard practice under any paver base — it separates the stone from the soil so the base doesn't pump down and clog. For decorative beds, fabric also suppresses weeds.
Can you compact #57 stone?
Only to seat it. #57 is open-graded and essentially self-compacting — running a plate compactor orients the particles (settling roughly 1", about 8%) but doesn't meaningfully increase its density the way it does with crusher run. That's why #57 is great for drainage but not for a load-bearing base on its own.
How many tons in a cubic yard of gravel?
Most crushed stone and gravel runs 1.4–1.7 tons per cubic yard. Lightweight lava rock can be as low as 0.55–0.7; dense river rock can reach 1.75. Use a material-specific density rather than a single average.
🗺️ Same Gravel, Different Name by Region
Compactable crushed-stone-plus-fines base is the single most-renamed material in the trade. Order the wrong name and you may get the wrong product. These are all functionally the same dense-graded base:
Decorative material availability also shifts regionally — lava rock is common in the Southwest and Hawaii, river rock in the Mountain West and Pacific Northwest, granite-derived crushed stone across the Southeast and New England, and limestone through the Midwest and Mid-Atlantic.
📚 Authority & References
The depths, densities, and compaction targets above come from the same primary sources cited in the calculator's methodology and standards blocks:
Get your exact gravel order
Enter your length, width, depth, and material into the free Gravel Calculator and get cubic yards, tons, and 0.5-cu-ft bag counts — with material-specific density, a compaction factor, and waste overage applied automatically. Supports rectangles, circles, and rings, plus a bag-vs-bulk recommendation.
Open the Gravel Calculator →Calculate Your Gravel Materials
Calculate cubic yards, tons, and 0.5-cu-ft bag counts for any rectangle, circle, or ring — with material-specific density, a compaction factor, and waste overage applied automatically.
Go to Gravel Calculator →