Pool Excavation Volume Calculator
Calculate the total excavation volume required for a swimming pool, including working space clearance and over-dig allowance for forms and waterproofing.
Formulas Used
Average Depth:
davg = (Shallow Depth + Deep Depth) / 2
Excavation Depth:
dexcav = davg + Over-Dig Allowance
Excavation Footprint Area:
- Rectangular: A = (L + 2·Ws) × (W + 2·Ws)
- Circular: A = π × ((D/2) + Ws)²
- Oval / Elliptical: A = π × (a + Ws) × (b + Ws)
Where Ws = working space clearance, a = semi-major axis, b = semi-minor axis.
Net Excavation Volume (bank measure):
Vnet = A × dexcav
Hauled / Loose Volume:
Vhaul = Vnet × (1 + Swell% / 100)
Unit Conversions:
1 CY = 27 CF | 1 CF = 0.028317 m³
Assumptions & References
- Pool depth transitions uniformly from shallow to deep end (trapezoidal cross-section); average depth = (shallow + deep) / 2.
- Working space clearance (typically 18 in – 3 ft) is added equally to all horizontal sides to allow room for forms, shotcrete equipment, and waterproofing crews.
- Over-dig allowance (typically 6 in – 1 ft) is added to depth for gravel base, plumbing, and leveling.
- Soil swell factor accounts for the expansion of excavated (bank) material into loose (hauled) material. Typical values: sand 10–15%, loam 20–25%, clay 25–35%, rock 30–40% (OSHA / USACE EM 1110-2-1911).
- Oval pool area uses the standard ellipse formula: A = π·a·b, where a and b are the semi-axes.
- Results represent gross excavation volume. Deduct any existing fill or spoil already removed on site.
- Always verify with a licensed geotechnical engineer for projects with unstable soils, high water tables, or slopes.
- References: USACE Engineering Manual EM 1110-2-1911; RS Means Site Work & Landscape Cost Data; APSP/ANSI-5 Standard for Residential Inground Swimming Pools.