Fick’s Law of Diffusion Calculator
💧 Diffusion, osmosis & transport. Use the Fick’s law of diffusion formula to find rate of diffusion, surface area, concentration difference, thickness: pick the value you want, type the others, and the answer updates as you go.
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Rate of diffusion | units |
| Surface area | cm² |
| Concentration difference | units |
| Thickness | µm |
Worked example
Find the rate of diffusion when Surface area = 10 cm², Concentration difference = 5 units, Thickness = 1 µm.
Using rate ∝ (surface area × difference in concentration)/(thickness of membrane): Rate of diffusion = 50 units.
Frequently asked questions
What is the formula for Fick’s law of diffusion?
rate ∝ (surface area × difference in concentration)/(thickness of membrane).
What do the letters stand for, and what units are used?
Rate of diffusion in units, Surface area in cm², Concentration difference in units, Thickness in µm.
How do you calculate rate of diffusion?
Put the values into rate ∝ (surface area × difference in concentration)/(thickness of membrane). For example, with Surface area = 10 cm², Concentration difference = 5 units, Thickness = 1 µm, rate of diffusion = 50 units.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (rate of diffusion, surface area, concentration difference, thickness) and fill in the others: it rearranges the formula for you.
