Soil Unit Weight Calculator
Enter void ratio, specific gravity of solids, and water content to instantly get total, dry, saturated, and submerged unit weights.
Soil Parameters
Volume of voids / volume of solids. Typical range: 0.3–2.0
Ratio of solid density to water density. Typical: 2.60–2.80
Mass of water / mass of dry solid × 100. Enter 0 for dry soil.
Common Presets
Total Unit Weight
γ (gamma)
—
kN/m³
Bulk weight including soil solids and pore water.
Dry Unit Weight
γd
—
kN/m³
Weight of solids only, no pore water counted.
Saturated Unit Weight
γsat
—
kN/m³
All voids filled with water; used at or above water table.
Submerged Unit Weight
γ' (buoyant)
—
kN/m³
Effective weight below water table (γsat − γw).
Derived Properties
Porosity (n)
—
Degree of Saturation
—
Unit Weight of Water
—
Formula Reference
γ = (Gs + S·e) · γw / (1 + e)
γd = Gs · γw / (1 + e)
γsat = (Gs + e) · γw / (1 + e)
γ' = γsat − γw
where γw = 9.81 kN/m³ · S = Gs·w/e
Summary
Enter void ratio, specific gravity of solids, and water content to instantly get total, dry, saturated, and submerged unit weights.
How it works
- Enter the void ratio (e) — ratio of void volume to solid volume, typically 0.3–2.0 for most soils.
- Enter the specific gravity of solids (Gs) — usually 2.60–2.80; 2.65 is the default for quartz sand.
- Enter the water content (w) in percent — mass of water divided by mass of dry solids.
- Click Calculate to get all four unit weights computed from classic soil mechanics formulas.
- Switch between kN/m³ and pcf using the unit toggle to match your project requirements.
Use cases
- Determine effective stresses in soil profiles for foundation design.
- Calculate overburden pressure and lateral earth pressures.
- Estimate buoyant forces on buried structures below the water table.
- Verify lab-derived soil index properties in geotechnical reports.
- Cross-check hand calculations during retaining wall or slope stability analysis.
- Quickly convert between SI and US customary unit weight values.