What is soil bulk density?

Bulk density is oven-dry soil mass divided by total sample volume, including pore space, typically expressed as g/cm^3 or kg/m^3.

Which moisture basis does this use?

Gravimetric moisture on a dry basis: water mass divided by oven-dry soil mass. Dry mass is computed from wet mass using md = mwet/(1 + w/100).

How do I measure core volume?

Measure inside diameter and height of the cylinder and compute V = pi*(d^2/4)*h in cm^3.

What are typical bulk density values?

Sands generally 1.5–1.7 g/cm^3; loams 1.2–1.5 g/cm^3; clays 1.0–1.4 g/cm^3. Organic soils can be much lower.

How is porosity estimated here?

If particle density (rho_s) is provided, porosity is n = 1 - rho_b/rho_s, reported as percent.

Can I use clod or paraffin methods?

This tool assumes cylindrical cores. If you have accurate displaced-volume from clod/paraffin methods, enter that volume directly.

Bulk Density of Soil Calculator

Q: Does compaction affect results?

Yes. Compaction raises bulk density. Use undisturbed cores and careful extraction, and oven dry at 105 C for consistency.

Inputs White Theme

Mass Input Mode *

I have oven‑dry mass (g)

I have wet mass and moisture (%)

Oven‑dry mass of soil (g) *

Core Volume *

I know the core volume (cm³)

I have cylinder dimensions (cm)

Core volume (cm³) *

Particle density \( \rho_s \) (g/cm³, optional)

If provided, porosity \( n = 1 - \rho_b/\rho_s \) will be calculated.

Tip: For undisturbed cores, trim flush ends and record precise dimensions.

Results

Dry bulk density

— g/cm³

In SI units

— kg/m³

Wet bulk density

— g/cm³

Porosity (optional)

— %

Ranges: sands ~1.5–1.7 g/cm³; loams ~1.2–1.5 g/cm³; clays ~1.0–1.4 g/cm³.

Example Data & Session Results CSV / PDF export

#	Timestamp	Mode	Dry Mass (g)	Wet Mass (g)	Moisture w (%)	Volume (cm³)	Dry BD (g/cm³)	Wet BD (g/cm³)	Porosity (%)
1	Example	Dry mass + known volume	150.00	—	—	100.00	1.50	—	43.40
2	Example	Wet mass + moisture + dimensions	—	300.00	10.00	98.17	2.78	3.06	—
3	Example	Dry mass + dimensions	120.00	—	—	125.66	0.96	—	63.70

Example rows are illustrative; use your measurements for actual records.

Reference: Typical Bulk Density by Soil Texture

Soil Texture	Typical Dry BD (g/cm³)	Typical Dry BD (kg/m³)	Notes
Sand	1.50–1.70	1500–1700	Low organic matter; large pores; compacts easily.
Loamy Sand	1.45–1.65	1450–1650	Coarse texture; moderate porosity.
Sandy Loam	1.40–1.60	1400–1600	Common in fields with moderate traffic.
Loam	1.20–1.50	1200–1500	Balanced texture; healthy rooting conditions.
Silt Loam	1.10–1.40	1100–1400	Higher water retention; prone to crusting.
Sandy Clay Loam	1.30–1.55	1300–1550	Compaction risk under heavy equipment.
Clay Loam	1.10–1.40	1100–1400	Fine pores; aeration may limit roots.
Silty Clay	1.00–1.35	1000–1350	Dense structure; drains slowly.
Clay	0.95–1.30	950–1300	High water holding; cracks when dry.

Values are broad field ranges; measure locally for management decisions.

Reference: Root Growth Limiting Bulk Density Thresholds

Texture Group	Caution ≥ (g/cm³)	Caution ≥ (kg/m³)	Severe ≥ (g/cm³)	Severe ≥ (kg/m³)	Interpretation
Coarse (sands)	1.60	1600	1.80	1800	Reduced root elongation; risk of drought stress.
Medium (loams)	1.55	1550	1.75	1750	Aeration and infiltration decline noticeably.
Fine (clays)	1.45	1450	1.60	1600	Strong root restrictions; frequent anaerobic pockets.

Thresholds are generalized; crop species and structure modify impacts.

Formulas Used

Core volume (cylinder): \\( V = \\pi \\frac{d^2}{4} h \\) where \(d\) and \(h\) are inside diameter and height (cm). Result \(V\) in cm³.
Gravimetric water content (dry basis): \\( w = \\frac{m_w}{m_d} \\times 100\\% \\). Hence dry mass from wet: \\( m_d = \\frac{m_{wet}}{1 + w/100} \\).
Dry bulk density: \\( \\rho_b = \\frac{m_d}{V} \\) in g/cm³. SI conversion: \\( \\rho_b(kg/m^3) = 1000 \\times \\rho_b(g/cm^3) \\).
Wet bulk density (if wet mass known): \\( \\rho_{b,wet} = \\frac{m_{wet}}{V} \\).
Porosity (optional, if particle density \\(\\rho_s\\) known): \\( n = 1 - \\frac{\\rho_b}{\\rho_s} \\) (expressed as %).

Typical particle density \(\\rho_s\) is ~2.65 g/cm³ for mineral soils; adjust if organic content is high.

How to Use This Calculator

Select your mass input mode: oven‑dry mass or wet mass plus moisture.
Provide core volume directly or enter cylinder dimensions to compute volume.
Optionally set particle density to estimate porosity from bulk density.
Click Calculate. Review dry and wet bulk density, and porosity.
Click Add example row to append a typical case for comparison.
Use Download CSV or Download PDF to save your table.
For accuracy, trim cores flush, avoid compaction, and oven‑dry at 105 °C.

FAQs

Bulk density is the mass of oven‑dry soil per total bulk volume, including pore space, typically expressed in g/cm³ or kg/m³.

Moisture is gravimetric on a dry basis: water mass divided by oven‑dry soil mass, expressed as a percentage.

Measure inside diameter and height of the cylindrical core using calipers, then compute \(V = \pi d^2 h / 4\) in cm³.

Sands: 1.5–1.7 g/cm³; loams: 1.2–1.5 g/cm³; clays: 1.0–1.4 g/cm³. Organic soils can be much lower.

If you supply particle density \(\\rho_s\), porosity is \( n = 1 - \\rho_b/\\rho_s \), reported as a percentage.

Yes. Compaction during sampling raises bulk density. Use undisturbed cores and careful extraction to minimize disturbance.

This tool assumes cylindrical cores. Clod/paraffin methods require displacement volume; you can input the resulting volume directly if measured accurately.