Set the ratio once, then run every ingredient line through it — answers come back in kitchen fractions where they fit.
Because measuring cups and spoons come in ¼s and ⅓s. When the scaled amount sits close to a kitchen fraction it’s shown that way (with the decimal alongside); when it doesn’t, you get the plain number and your own judgement.
Seasoning, chilli, leavening and cooking time. Scale those with restraint — a doubled cake needs more time, not double time, and double the chilli is a decision, not arithmetic.
Yes — 12,5 and 12.5 both work, and thousands separators are fine
(1,234.56 or 1.234,56). A lone comma followed by exactly three digits,
like 1,234, is read as one thousand two hundred thirty-four.
Entirely in your browser. Numbers you type are never sent anywhere — there is no server doing the math, no analytics watching you do it.