Excavation Calculator

Bank Volume vs Loose Volume

Excavated soil takes up more space than it did in the ground. Bank volume is the volume of soil in its compacted, in-place state — exactly what you compute from length × width × depth. Loose volume is what you actually haul in a dump truck, and it is larger because the soil grains rearrange and trap air when disturbed. The ratio of loose to bank volume is called the swell factor, and it varies by soil type.

Typical Swell Factors by Soil Type

Dry sand bulks up about 12 percent. Loam and topsoil swell 25 percent. Dense clay swells 30 to 40 percent because it fractures into chunks. Weathered rock can swell 40 to 50 percent, and blasted hard rock 50 to 65 percent. If you do not know your soil, use 25 percent as a safe residential default. For hauling contracts, always quote loose cubic yards, not bank yards.

Foundation and Basement Excavation

A full basement is typically 8 to 9 feet deep below grade, with an extra 12 inches of over-dig around the perimeter for waterproofing and form work. A shallow crawl space is 3 to 4 feet deep. Footings alone need to reach below the local frost line — 42 to 48 inches in northern states, 12 inches or less in the Deep South. Always check with your local building department before you start digging.

Call 811 Before You Dig

In every US state, contacting 811 at least three business days before starting excavation is required by law. A free utility locator service will mark underground gas, electric, water, sewer, phone, and fiber lines on your property. Cutting a live line can injure workers and cost thousands to repair. Keep the markings visible throughout the project.

Typical Excavation Volumes

Common residential projects with bank cubic yards and loose (truck-hauled) cubic yards at 25% swell:

Weight check: dry loam runs about 2,200 lb/cu yd; wet clay 3,000+ lb/cu yd. A 10 CY truck hauling wet clay can hit 15 tons — close to its legal load limit. Wet soil hauling always costs more than dry because of extra truck trips.

Frequently Asked Questions

How much does a cubic yard of dirt weigh?

Dry loam weighs about 2,200 lb/cu yd. Wet clay can exceed 3,000 lb/cu yd. A 10-cu yd dump truck of soil often weighs more than its volume rating allows.

How do I figure dirt for a round pool?

Select the circular shape option and enter the diameter as length. The calculator uses π × r² × depth automatically.

What is bank cubic yards vs loose cubic yards?

Bank is the compacted in-place volume. Loose is what a truck hauls after the soil bulks up by the swell factor.

Can I keep excavated soil on site?

Often yes — topsoil can be stockpiled and reused for landscaping. Subsoil may be used to backfill, grade, or raise low spots. Check local codes for fill-dirt permits.

How deep is a typical footing trench?

Below the frost line (42-48 in northern states) and at least 12 inches into undisturbed soil. Width is typically 2× the foundation wall thickness.