About
How the tools compute their results, what data they use and how they are checked.
CALX gathers 126 scientific calculators and converters, from high school to the laboratory. Each tool states the formula used, the model's assumptions and, where needed, the sources of the data it uses.
01
Formula and assumptions
The formula used is displayed with the values entered. The "Calculation, assumptions and sources" section states the definitions used, the model's assumptions and its domain of validity.
02
Sources
Some tools use exact mathematical relations. Others use constants or data from primary sources: SI definitions, IUPAC values, scientific articles or datasheets.
These sources are given with their reference and, where applicable, their consultation date. When a value is found on a third-party site, its original source is looked up before it is used.
03
When the calculation is undefined
Some results cannot be represented by a number. An object placed at the focus of a lens gives an image at infinity. An impossible triangle is refused. A yield above 100% is displayed as computed and flagged as an anomaly.
When a quantity cannot be determined from the data entered, the result is shown as "not determined".
04
Tests
Results are checked with several kinds of tests: published reference values, mathematical identities, conservation of physical quantities and model boundaries.
More than 5,754 tests check the results. The site is only published when all of them pass.
05
Data and privacy
Calculations run in the browser. The values entered are not sent to a server.
The privacy policy describes in particular how share links, advertising and audience measurement work.