Science should feel a little clearer.

Made for understanding

These tools are for students, educators and anyone who needs a straightforward absorbance calculation or calibration graph. All four launch tools and their basic exports are free, with no account required.

Transparent by design

The tools use deterministic equations, ordinary least squares with an intercept, and user-supplied coefficients or standards. We show units, working and assumptions alongside the result. Examples are synthetic teaching data, not measurements of real substances.

Calculations, pasted tables and uploaded CSVs are processed in your browser. They are held in memory and cleared when you leave or reload the tool. You decide whether to download a result.

A calculation has limits

Correct arithmetic does not establish experimental accuracy, instrument performance or suitability of a laboratory method. The tools do not identify substances, interpret clinical results or certify laboratory compliance. High R² is not proof that a calibration is appropriate. Uncertainty estimates are outside this first release.

Built on established references

• IUPAC: absorbance
• IUPAC: Beer–Lambert law
• NIST: data analysis and model validation
• NIST: calibration of future measurements

A small, independent experiment

Absorbance is owned and operated by Pacific Fund. We are learning which tools people find useful before deciding what to build next. No paid products or subscriptions are offered at launch.

Found a calculation issue, have a teaching idea, or want to tell us what would help? Specific feedback makes this project better.