Hole Volume Calculator — Soil & Excavation
Digging a post hole, planting pit, or trench? Enter the shape and dimensions to instantly find the volume of soil to be removed (in cubic metres and litres), the wall area (for lining or concrete formwork), and the total inner surface area for coating or waterproofing estimates.
Hole shape
m
m
Volume of earth or material excavated from the hole
0.0353 m³
- 1
Base area
π × 0.15² = π × 0.0225 = 0.0707V = π × r² × depth. - 2
Volume
0.0707 × 0.5 = 0.0353
How does this calculator work?
Cylinder hole: V = π × r² × depth; Wall area = 2πr × depth. Rectangular hole: V = l × w × depth; Wall area = 2(l+w) × depth. Enter radius (or length and width) and depth in metres to get volume in m³ and litres, wall area, base area, and total inner surface for lining estimates.
Formula
How this is calculated
A hole is simply a negative solid: a cylinder or rectangular prism removed from the ground. For a cylindrical hole (fence posts, pile foundations, tree plantings) the volume is the area of the circular cross-section — π × r² — multiplied by the depth. The lateral wall area wraps around the circumference (2π × r) over the full depth, and the base is the same circular area as the cross-section.
For a rectangular hole (trenches, footings, planters) the volume is length × width × depth. The four walls have area 2 × (length + width) × depth, and the base area equals length × width. The total inner surface (walls + base) is useful when calculating how much membrane, concrete, or render you need to line or coat the hole.
All dimensions are in metres; volume is in cubic metres (m³) and is also shown in litres (1 m³ = 1 000 L). To convert to cubic yards multiply by 1.308; to cubic feet multiply by 35.315. The calculator does not account for soil compaction or swell — bulk soil expands approximately 20–30% when excavated, so plan for extra removal volume if you are hauling material away.
Frequently asked questions
The volume of concrete equals the hole volume minus the cross-sectional area of the post times the depth. For a 15 cm radius hole and a 10 cm × 10 cm (0.01 m²) timber post 0.5 m deep: hole volume = π × 0.15² × 0.5 ≈ 0.0353 m³, post volume = 0.01 × 0.5 = 0.005 m³, so concrete needed ≈ 0.030 m³ = 30 L.
Volume is the geometric quantity in m³; mass depends on the density of the soil. Typical soil densities: dry sand ≈ 1 450 kg/m³, loam ≈ 1 200 kg/m³, clay ≈ 1 800 kg/m³. Multiply the calculated volume by the soil density to estimate the mass of excavated material.
Wall area tells you how much surface needs to be lined, sealed, or formed. For example, installing a waterproof membrane in a foundation trench, applying concrete formwork, or calculating how much timber shuttering is needed. The base area is also important for slab thickness calculations.
Also known as
TG we-Calculate Editorial Team. (2026). Hole Volume Calculator — Soil & Excavation [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/hole-volume-calculator
TG we-Calculate Editorial Team. "Hole Volume Calculator — Soil & Excavation." TG we-Calculate. 2026. https://we-calculate.com/calculator/hole-volume-calculator.
TG we-Calculate Editorial Team, "Hole Volume Calculator — Soil & Excavation," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/hole-volume-calculator
@misc{wecalculate_hole_volume_calculator, title = {Hole Volume Calculator — Soil & Excavation}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/hole-volume-calculator}}, year = {2026}, note = {TG we-Calculate} }
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