How to use the particle settling velocity calculator
Find how fast a small sphere settles through a fluid using Stokes law. Enter particle density, fluid density, particle radius, dynamic viscosity in the fields above; the settling velocity are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “settling velocity”, “sediment settling speed”, “Stokes law sphere”, “calculate particle settling velocity”, “find settling velocity”.
Formula
Variables
- dp — Particle density (kg/m³)
- df — Fluid density (kg/m³)
- r — Particle radius (µm)
- mu — Dynamic viscosity (Pa·s)
Worked example
With particle density = 2650 kg/m³, fluid density = 1000 kg/m³, particle radius = 50 µm, dynamic viscosity = 0.001 Pa·s, the calculator gives settling velocity ≈ 0.00898943 m/s; settling velocity ≈ 8.989429 mm/s.
Frequently asked questions
What is the particle settling velocity calculator used for?
Find how fast a small sphere settles through a fluid using Stokes law. It helps with questions such as “settling velocity”, “sediment settling speed”, “Stokes law sphere”.
What is the formula for the particle settling velocity calculation?
Settling velocity (m/s) = 2 / 9 × (dp-df) × GRAV × (r × 1e-6)^2 / mu. Settling velocity (mm/s) = [Settling velocity] × 1000. Here dp is particle density (kg/m³), df is fluid density (kg/m³), r is particle radius (µm), mu is dynamic viscosity (Pa·s).
What inputs do I need for the particle settling velocity calculator?
You need particle density in kg/m³, fluid density in kg/m³, particle radius in µm, dynamic viscosity in Pa·s. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the particle settling velocity calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the particle settling velocity result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.