TotalCalcs. Material Calculators

Road Base Calculator

Find out exactly how much road base (crusher run) your driveway, sub-base, or patio needs — in tons, cubic yards, bags, and estimated cost.

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Depth:
4″ under patios/walkways, 6–8″ for driveways.
Sets the density used to convert volume → tons.
Recommended — road base settles ~20% when compacted.
Road base / crusher run often runs ~$18–40 / ton delivered.

You will need

Bags assume 0.5 cu ft each (≈50 lb bag). Tons are US (short) tons. Includes the 20% compaction allowance when ticked — always round up and confirm with your supplier.

How much road base do I need?

Road base (also called crusher run or dense-grade aggregate) is sold by the ton or cubic yard. Work out the volume, then convert:

Cubic yards = length (ft) × width (ft) × depth (ft) ÷ 27. Multiply cubic yards by the density to get tons. Road base packs tight and weighs roughly 1.5 tons per cubic yard.

As a rule of thumb, one ton of road base covers about 90 square feet at 2 inches deep, or roughly 45 sq ft at 4 inches.

How deep should road base be?

UseDepth
Patio / walkway base4 inches
Driveway base6 inches
Heavy loads / soft or clay soil8 inches (in two layers)
Under a paver bedding layer4–6 inches

Road base densities used

TypeDensity (tons / cu yd)
Crusher run / dense grade1.50
#21AA limestone road base1.50
Aggregate base course (ABC)1.55

Densities are typical averages; actual weight varies with moisture and quarry. Use them as a close estimate.

Road base FAQs

How much road base do I need for a driveway?

Multiply length × width × depth (all in feet) to get cubic feet, divide by 27 for cubic yards, then multiply by about 1.5 for tons. For example, a 40 × 10 ft driveway at 6 inches deep needs about 8.9 cubic yards, or roughly 13.3 tons of crusher run (with a 20% compaction allowance).

How many tons are in a cubic yard of road base?

About 1.5 US tons per cubic yard for crusher run and dense-grade road base, since the mix of stone and fines packs tightly. Aggregate base course (ABC) can be slightly heavier at around 1.55 tons.

What is the difference between road base and crusher run?

They are essentially the same thing — a dense-graded blend of crushed stone and stone fines that compacts into a hard, stable surface. Names vary by region: crusher run, road base, dense grade, #21AA, and ABC all describe this fines-plus-stone base material.

How much area does a ton of road base cover?

About 90 square feet at 2 inches deep, or roughly 45 square feet at 4 inches. One cubic yard (≈1.5 tons) covers about 80 sq ft at 4 inches.

Why add 20% for compaction?

Road base is meant to be compacted, and it settles roughly 15–20% as it is tamped to its finished depth — so you need to buy that much extra. Leaving the “Add 20% for compaction” box ticked covers this plus minor waste.

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