Excavation Volume Calculator — ft to yd³, truck loads, cost
How to use this calculator
Select an excavation shape (rectangular, trapezoidal with sloped sides, circular, or trench), enter dimensions in feet, inches and fractions, and choose the soil type to apply the correct swell factor. Results update instantly with bank volume (in-ground), loose volume (after excavation), weight, and truck loads.
Swell factor — excavated soil expands when removed from the ground. Clay swells 30-40%, sand 10-15%, rock 40-60%. The calculator applies this factor automatically to compute hauling volume.
Cost — price per cubic yard or per truck load for disposal.
Saved Calculations
| Time | Shape | Soil | Bank yd³ | Loose yd³ | Trucks | Cost |
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How to Calculate Excavation Volume
This excavation calculator estimates bank volume (in-ground, undisturbed) and loose volume (after excavation with swell) in cubic yards. Enter dimensions in feet, inches and fractions for four common shapes: rectangular pit, trapezoidal (sloped sides for safety per OSHA 29 CFR 1926 Subpart P), circular (wells, piers), and trench (utilities, footings).
Swell Factor Explained
When soil is excavated, it breaks apart and occupies more space than in its original compacted state. This increase is called the swell factor. Loose Volume = Bank Volume × (1 + Swell%). Typical values: Clay 30-40%, Sand/Gravel 10-15%, Topsoil 20-30%, Rock 40-60%, Shale 35-45%. Always use loose volume for trucking calculations.
Formulas
Rectangular: L × W × D ÷ 27 = yd³. Trapezoidal: L × ((Top W + Bottom W) / 2) × D ÷ 27. Circular: π × r² × D ÷ 27. Trench: L × W × D ÷ 27. Average soil weight: 2,200 lb/yd³ bank (varies by type).
FAQ
How many truck loads for a basement? A typical 30×40×8 ft basement = 356 yd³ bank. With 25% swell = 444 yd³ loose. At 10 yd³/truck = 45 loads. Why use trapezoidal shape? OSHA requires sloped sides in excavations deeper than 5 ft (1.5:1 slope for Type C soil). What is bank vs loose volume? Bank = undisturbed soil in-ground; loose = same soil after excavation, expanded due to swell.
