Scale ingredients up or down.
Scales any ingredient amount by the ratio of desired to original servings.
Note: cooking times don't scale linearly — a double batch takes longer than 2×.
Pan size is another thing that doesn't scale simply — doubling a recipe often means the batter or dough no longer fits standard bakeware, so check pan capacity before assuming a straight multiplication works end to end.
Recipe for 4 servings, scale to 6, ingredient 200 g: 200 × (6/4) = 300.00.
Start with a smaller ratio (~75%) for salt, spices, and hot elements. Adjust to taste.
Trickier than cooking — chemistry-heavy recipes (breads, cakes) can misbehave. Best to run the original recipe multiple times.
These often don't scale linearly either — doubling a recipe rarely means doubling the baking soda or powder exactly, since too much can affect texture and flavor.