304 Limestone: Ohio's Go-To Base Stone Explained
304 limestone is a dense-graded crushed stone base named after Ohio Department of Transportation specification Item 304, aggregate base. It runs from about 2 inches down to fine dust, and that range of sizes compacts into a dense, load-bearing layer. Contractors in Ohio and nearby states use it under asphalt driveways, concrete slabs, parking areas, and pole barns. You may also hear it called “304 crushed limestone,” “304 base,” or simply “304.”
Volume and tonnage calculator →Size and makeup
- Top size: about 2 inches, with stones of many sizes plus fines.
- Material: crushed limestone, though some suppliers offer 304 made from gravel or recycled concrete.
- Behavior: packs tight and hard when compacted at proper moisture.
The fines are what make 304 lock together, so it drains more slowly than clean stone. Exact gradation follows the specification and quarry, so check product data if needed.
304 vs other common stone
| Product | Size | Fines? | Typical use |
|---|---|---|---|
| 304 limestone | About 2 inches to dust | Yes | Base under driveways and slabs |
| #57 limestone | About 1 inch to 1/2 inch | No | Drainage, clean driveway topping |
| #8 limestone | About 3/8 to 1/2 inch | No | Paver bedding, drainage |
| Limestone screenings | Dust and small chips | Mostly fines | Leveling, paver bedding, paths |
Many gravel driveways use 304 as the base and a cleaner, smaller stone on top for a neater surface.
Weight and how much to order
304 typically weighs around 1.4 to 1.5 tons per compacted cubic yard. To estimate:
- Multiply length by width for square feet.
- Multiply by compacted depth in feet (4 inches = 0.333 feet, 6 inches = 0.5 feet).
- Divide by 27 for cubic yards.
- Multiply by about 1.45 tons per yard.
- Add 10 to 15 percent for compaction and waste.
Example: a 12 x 60 foot driveway at 6 inches: 720 x 0.5 = 360 cubic feet, divided by 27 = 13.3 yards, times 1.45 = about 19.3 tons, or about 21 to 22 tons with extra.
See four-inch gravel base tonnage or use the base calculator.
Typical depths
- Walkways and patios: about 4 inches.
- Residential driveways: about 6 to 8 inches, more on soft soils.
- Pole barns and equipment pads: 6 inches or more.
- Under asphalt paving: depends on traffic and soil; many residential jobs use 6 to 8 inches.
Installation tips
- Remove sod and topsoil down to firm ground.
- Use a geotextile fabric on clay or wet soils to keep the base from mixing into the mud.
- Spread in lifts and compact each with a plate compactor or roller.
- Keep the stone slightly damp while compacting.
- Crown or slope the surface so water drains off.
Bottom line
304 limestone is Ohio’s standard dense-graded base stone, roughly 2-inch minus with fines, that compacts into a firm base for driveways, slabs, and parking areas. Figure about 1.4 to 1.5 tons per compacted yard, add extra for compaction, and install in compacted lifts.
Questions people ask
What does 304 limestone mean?
It refers to Ohio DOT Item 304, a dense-graded aggregate base specification, commonly made from crushed limestone.
How big is 304 limestone?
Roughly 2 inches down to fine dust, depending on the supplier.
Is 304 good for a driveway?
Yes, especially as a base. Many driveways top it with a smaller clean stone for a neater surface.
How much does 304 limestone weigh per yard?
Around 1.4 to 1.5 tons per compacted cubic yard.
Does 304 limestone drain well?
It drains more slowly than clean stone because of its fines, but it compacts very firmly.
Related guides
- CA6 Gravel: What It Is and How Much You Need
- Crusher Run Driveway: Depth, Tons and How to Build It Right
- Limestone Gravel Driveway: Pros, Cons, Sizes and How It Holds Up
- How Many Tons Is a 4-Inch Gravel Base?
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