Recipe Scaling Factor

This formula adjusts a recipe by the same proportion as the serving size changes. If you want more servings, you multiply each ingredient by the ratio of desired servings to original servings; if you want fewer, the ratio is less than 1, so the amounts shrink. It works because the recipe is assumed to scale linearly: each serving uses the same fraction of every ingredient.

Use this when you need to cook a recipe for a different number of people than the recipe was written for. It is also useful when doubling, halving, or otherwise resizing batch recipes for baking, drinks, soups, or meal prep.

• multiplying by the wrong ratio, such as have/want instead of want/have
• scaling only one ingredient and forgetting to scale the others
• using the formula for recipes with non-linear ingredients, like salt or spices that may need taste adjustments rather than exact scaling