The calculator accepts endpoint geometry in CSS pixels because design handoffs commonly specify viewport and size points that way. Output can keep fixed terms in px or divide them by an entered root size to express them in rem. Neither choice turns a CSS pixel into a physical device pixel, and neither selects an accessible typography system automatically.
Pixel output keeps the endpoint units direct
With px output, lower bound, intercept and upper bound remain in CSS pixels while the changing term uses vw. This makes the connection to entered values easy to inspect. It also means those fixed terms do not scale merely because a user changes the browser's root font preference. Whether that is suitable depends on the property and the project, not on the arithmetic alone.
Rem output divides fixed terms by the chosen root
For a 16px root, 16px becomes 1rem and 32px becomes 2rem. The intercept is divided by the same root. This serialization assumes that the root used during rendering matches the root entered during generation when you compare exact px endpoints. If the actual root changes, the rem terms respond while the vw term does not, so the rendered mapping intentionally changes.
Units do not replace layout and zoom testing
A generated token can be mathematically consistent and still be wrong for the actual content. Long translations, font metrics, line length, user zoom, minimum readable sizes and surrounding constraints all matter. Preview the real component, test intermediate widths and zoom, and choose endpoints with enough margin. ClampCalc reports its numeric contract; it does not certify accessibility or design quality.