Diffusion Coefficient Calculator
Free calculate diffusion coefficient using einstein-smoluchowski equation with temperature, viscosity, and particle radius.
Enter Parameters
Water at 20°C: ~0.001 Pa·s
Typical molecule: 0.1-1 nm
J/K
Default: 1.381 × 10⁻²³ J/K
Results
Enter parameters to calculate diffusion coefficient
Diffusion Coefficient Formula
Einstein-Smoluchowski Equation
D = kT / (6πηr)
- • D = Diffusion coefficient (m²/s)
- • k = Boltzmann constant (1.381×10⁻²³ J/K)
- • T = Absolute temperature (K)
- • η = Dynamic viscosity (Pa·s)
- • r = Particle radius (m)
Key Concepts
- • Diffusion coefficient measures molecular mobility
- • Higher temperature increases diffusion
- • Larger particles diffuse slower
- • Higher viscosity reduces diffusion
- • Typical range: 10⁻¹⁰ to 10⁻⁶ m²/s