Estimate volume in cubic yards and total material cost.
This calculates the raw material volume only; always order slightly more than calculated to account for uneven ground and spillage.
It multiplies the driveway's length, width, and desired depth to get volume, then converts to the units your material (gravel, concrete, asphalt) is sold in.
This varies by material and expected vehicle weight, but gravel base layers are commonly 4-8 inches, with the top surface layer added on top.
Yes — loose gravel compacts down once driven on or rolled, so many contractors order 10-20% extra to compensate.