Question 1

How do I calculate gravel for a circular driveway?

Accepted Answer

For circular areas, use the formula: π × radius² × depth ÷ 27 = cubic yards. Measure from the center to the edge for the radius. For example, a 20-foot diameter circle has a 10-foot radius.

Question 2

What is the best gravel for drainage?

Accepted Answer

For drainage, use clean angular gravel like #57 stone or pea gravel. Avoid crusher run or gravel with fines (dust) as these can impede drainage. Size should be 3/8" to 3/4" for most drainage applications.

Question 3

How much does gravel compact?

Accepted Answer

Gravel typically compacts 10-20% depending on the type and installation method. Crusher run compacts more than clean stone. Always add 10-15% extra to account for compaction and settling.

Question 4

What's the difference between #57 stone and pea gravel?

Accepted Answer

#57 stone is angular, crushed limestone about 3/4" in size, ideal for driveways and drainage. Pea gravel is rounded, smooth stones about 3/8" in size, better for decorative applications and walkways.

Question 5

How deep should gravel be for a driveway?

Accepted Answer

For residential driveways, 2-3 inches of gravel is typical. Heavy-use driveways may need 4 inches. Always install over a compacted base and consider using geotextile fabric underneath.

Question 6

Do I need a base under gravel?

Accepted Answer

Yes, a properly prepared base is crucial. Remove organic material, compact the subgrade, and consider adding a layer of larger stone (like #2 or #3) as a base before applying the finish gravel.

Gravel Calculator: Driveways, Paths & Bases

Types of Gravel & Aggregate

Recommended Gravel Depths

Installation Best Practices

Gravel Weight Reference

Lightweight

Standard

Heavy

Gravel Calculator FAQ