ToolsSite InvestigationFieldwork

Percent Solids in Slurry Calculator

Calculate percent solids by weight and volume from slurry, solid, and fluid densities. For drilling mud checks, grout QA, and slurry pipeline design.

Last updated 14 July 2026

About this tool

Calculate the percent solids in a slurry or suspension from three density measurements: slurry density, solid particle density, and carrier fluid density. Returns solids concentration by weight and by volume.

Used for drilling mud QA (checking bentonite concentration), grout mix verification, slurry pipeline design, and contaminated land sediment analysis. Also gives the solid-to-liquid ratio by weight.

All you need is a mud balance reading (slurry density) and knowledge of the solid and fluid densities. No lab testing required beyond the density measurement.

How to use this tool

1. Enter the slurry density — from a mud balance or hydrometer. Must be between fluid and solid density.

2. Enter solid and fluid densities — defaults are quartz (2650 kg/m³) in water (1000 kg/m³). Adjust for bentonite, cement, etc.

3. Read the percent solids and solid:liquid ratio — by weight and by volume.

Technical information

Cv = (ρ_slurry − ρ_fluid) / (ρ_solid − ρ_fluid) — volume concentration

Cw = Cv × ρ_solid / ρ_slurry — weight concentration

Solid:liquid ratio = Cw / (1 − Cw)

Limitations

Assumes a two-phase system (solid + liquid) with no air entrainment. Aerated slurries will give incorrect results — deair the sample before measuring density.

Assumes all solids have the same density. For mixed-mineral slurries (e.g. bentonite + cement + soil cuttings), use a weighted average solid density or measure directly.

Revision history

14 July 2026: Initial release

Disclaimer

This tool is provided for educational and general information purposes only. It is not a substitute for professional engineering advice, design or verification.

Diggy and its contributors are not licensed engineering consultants and no results generated by this tool should be used directly for construction, design or safety-critical decisions.

All values and outputs are based on published empirical correlations and should be independently checked and confirmed by a qualified geotechnical engineer before use.

By using this tool, you accept full responsibility for how you interpret and apply the information provided.

Spotted an error? Let us know.

Slurry density (kg/m³)

Measured density of the slurry or mud. Must be between fluid and solid density.

Solid particle density (kg/m³)

Quartz/soil: ~2650. Bentonite: ~2600. Cement: ~3150.

Fluid density (kg/m³)

Water: 1000. Seawater: ~1025.

Related tools