Why weigh?
A spoonful isn't a fixed amount. Salt crystals vary so much that a teaspoon of one brand can weigh twice as much as another, and flour packs differently every time it's scooped. A kitchen scale takes the guesswork out.
Percentages make recipes portable. Once a recipe is written as percentages — salt as 2% of the cabbage, water as 72% of the flour — it scales to any batch, from one jar to a crock, one loaf to a bakery's worth. These calculators turn the percentages into grams for your batch — and the baker's calculator also works backwards, from a recipe's grams to its percentages.