DiffusionCalculator.com started with one goal: to make diffusion calculations — Fick's laws, diffusion coefficients, diffusion lengths — quick, correct and understandable. We have since added the core laws of chemistry and physics, because the same students, engineers and researchers need those every day too.
What makes our calculators different
- Solve for any variable. Every equation is rearranged for each unknown, not just the obvious one.
- Units handled properly. Inputs are converted to SI internally, using CODATA 2018 values for physical constants (R, kB, F, NA, e, G).
- Transparent working. Step-by-step working shows the formula and the SI values, so you can check the result or learn the method.
- Explanations included. Each page states the law, explains when it applies and gives a worked example.
- Private by design. All calculations run in your browser. We don't collect what you type.
Who it's for
Students in chemistry, physics, materials science, chemical and biomedical engineering. Teachers preparing problem sets. Engineers and scientists who need a reliable answer fast.
Accuracy
We test every calculator by solving for each variable and checking that the results round-trip consistently. If you spot an error or would like a new calculator, please contact us.