Convert meters and °F, not rem

Length, mass, US volume, and file size in one tool; Celsius and Fahrenheit in another. Recipe cups and CSS rem live elsewhere.

A US recipe in cups, a UK weather report in Celsius, a parcel in pounds that a form wants in kilograms. Unit pages do factor math. They are not a freight class calculator and not NIST calibration.

Two doors on purpose

• Unit converter is the pillar for length, mass, volume, and similar families you pick on the form.
• Celsius to Fahrenheit is the supporting URL for the pair people type. Same arithmetic, narrower H1.

CSS unit converter is rem/em/px at an assumed root font size — design, not kilograms. Percentage “what is 15% of 80” is the percentage calculator, not a unit.

SI math, CSS, and money are split on purpose

The general converter is length/mass/volume. C↔F is a supporting URL. CSS rem/px assumes a root font-size. Percent-of is the percentage calculator. No FX rates, no customs class, no NIST sticker.