basic

Fick's First Law Diffusion Flux Calculator

J = − D · (dC / dx) — molar flux due to a concentration gradient.

Compute the steady-state diffusive molar flux J (mol·m⁻²·s⁻¹) across a region of concentration gradient dC/dx (mol·m⁻⁴) using Fick's first law: J = −D · dC/dx, where D is the diffusion coefficient (m²/s). Negative sign indicates net flow from high to low concentration.

Dr. Helena Ortiz By Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

m²/s
mol/m⁴

Results

Enter values and click Calculate to see results.
Was this helpful?

How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

J = − D · (dC / dx).

In depth

Compute the steady-state diffusive molar flux J (mol·m⁻²·s⁻¹) across a region of concentration gradient dC/dx (mol·m⁻⁴) using Fick's first law: J = −D · dC/dx, where D is the diffusion coefficient (m²/s). Negative sign indicates net flow from high to low concentration.