Excavation Calculator

Measure the length, width, and depth of the area you plan to dig — all in feet — and enter them. The excavation calculator instantly returns the cubic yards of dirt to excavate. Open More options to pick a soil type (which sets the swell factor), set your real truck capacity, or add a per-yard price to estimate haul-away cost. To answer *how many cubic yards of dirt to excavate* for most jobs, those three measurements are all you need — everything else is optional.

Soil sitting in the ground is compacted — this is called bank volume, and it is the number you actually excavate. The moment you dig it out, the soil breaks apart and traps air, so it swells and takes up more room in the truck. That larger figure is the loose volume, and it is what really decides *how many truck loads of dirt* you haul away. A typical swell (bulking) factor is about 15% for sand and gravel, 25% for common earth and loam, and 30% or more for heavy clay. This excavation calculator with a swell factor shows both numbers so you order the right dumpster or book the right number of loads instead of guessing.

Bank volume (yd³) = (Length × Width × Depth in ft) ÷ 27
Loose volume (yd³) = Bank volume × (1 + swell %)
Truck loads = Loose volume ÷ truck capacity (round up)

There are 27 cubic feet in one cubic yard. For example, a 20 ft × 10 ft area dug 3 ft deep is 600 cubic feet, or 600 ÷ 27 = 22.22 cubic yards of bank material to excavate.

How much dirt for a 20×10 foundation dug 3 ft deep? 20 × 10 × 3 = 600 ft³ = 22.22 cubic yards to excavate. At a 25% swell that is 27.78 loose yards — about 3 loads in a 10-yard dump truck.

A 4 ft wide, 50 ft long trench, 4 ft deep: 4 × 50 × 4 = 800 ft³ = 29.63 cubic yards of bank dirt.

A small 8×8 pad, 6 in (0.5 ft) deep: 8 × 8 × 0.5 = 32 ft³ = 1.19 cubic yards.

- Dig to the deepest point. For a sloped or uneven bottom, measure the *average* depth.
- Add 10–20% for over-excavation on footings and trenches — walls slough and you rarely dig a perfect box.
- Match the truck. A standard tandem dump truck legally carries about 10–12 cubic yards; a tri-axle carries more. Set your real capacity under More options.
- Call 811 before you dig to locate buried utilities — it is free across the US.
- Confirm the swell factor with your hauler if you pay for disposal by the loose cubic yard.