Gravel Calculator: Cubic Yards and Tons of Base

The gravel calculator formula

Area times depth in feet, divided by 27, because a cubic yard is 27 cubic feet. Same volume step as our concrete cubic yard calculator.

Nobody sells base by the yard off a chute. It moves by the ton across a certified scale, so yardage becomes weight before it becomes money.

Tons per cubic yard varies by material

A state DOT study measured conversion factors on nine real aggregates. Every row is a range, not a constant.

Those are compacted weights. Wisconsin DOT pays completed in place dense base at a flat 1.85 tons per cubic yard.

SimplyWise Cost Estimator turns a photo into an itemized, branded estimate in about 6 seconds.

Worked example: a 12 by 40 driveway

Area is 480 sq ft. New York DOT specifies 6 in of subbase under a paved residential driveway, so take depth as 0.5 ft. That is 240 cubic ft, or 8.89 cubic yards compacted.

At 1.85 that is 16.44 tons. The measured 1 1/4 in dense base range gives 15.9 tons at 1.79, 17.6 at 1.98. Order 16 to 18 tons.

Loose dense base takes 34 to 52 percent more room, so stage for about 12 to 13.5 yards.

Worked example: a 16 by 20 patio at 4 in

Area is 320 sq ft at 0.333 ft deep, so 106.7 cubic ft, or 3.95 cubic yards.

At 1.85 that is 7.31 tons. Switch to recycled concrete base at 1.65 to 1.75 and the same hole takes 6.5 to 6.9 tons. Federal Highway explains it: recycled concrete has a lower compacted unit weight, so it yields more volume per ton.

Gravel calculator reference table: area and depth

Compacted cubic yards, tons at the 1.85 factor.

Moisture is on the ticket whether you like it or not

The agencies buying the most aggregate write moisture rules. Wisconsin requires base over 7 percent moisture to be dried or the excess deducted from measured weight. Texas pays flexible base by dry weight.

Nobody docks your supplier for you. A rainy delivery and a dry one differ on the same ticket.

Sand, gravel, and the one thing nobody publishes

Sand and bank run gravel do have published densities, as earthwork figures rather than WisDOT pay factors. The Federal Highway 2022 shrinkage and swell table, reprinted as Table A.4 of the Wisconsin study, puts compacted dry sand at 1,920 kg per cubic meter, about 1.62 tons per cubic yard, and well graded dry gravel at 2,450, about 2.06 tons per cubic yard. Use those to sanity check a supplier, not to settle an invoice.

What genuinely is not published is a base depth for patios or walkways. New York DOT calls for 6 in of subbase under a paved residential driveway, up to 12 in for heavy trucks, and the residential code calls for 4 in of base under a slab below grade.

Run the gravel calculator in this order

1. Get compacted volume first

   Area times depth in feet, divided by 27. That is the finished hole, not the delivered pile.

2. Convert with the right material factor

   Use a range, not one number. Recycled base and granular backfill weigh less per yard.

3. Size the lifts before you order

   Minimum lift is twice the top stone size. Ohio DOT caps compacted lifts at 8 in behind a heavy vibratory roller, 4 in without one.

4. Quote a tonnage band

   Give a range with the moisture caveat, then reconcile against the scale tickets.