Recipe Scaler: The Math of Cooking for More (or Fewer) People

Recipe scaling seems straightforward — double the ingredients, double the yield. Most of the time that's correct. A few categories of ingredients and techniques require more care.

What Scales Linearly

Everything in a well-written recipe scales linearly by default. If a recipe for 4 serves uses 2 cups flour, a recipe for 8 serves uses 4 cups. If it uses 1 teaspoon salt, scale to 2 teaspoons. This works for virtually all of the ingredients in most recipes.

What Doesn't Scale Linearly

Salt and strong spices. When doubling, start with 1.5× (not 2×) and adjust to taste. The relationship between salt concentration and perceived saltiness is roughly logarithmic — double the salt doesn't taste twice as salty, but it can easily taste too salty.

Baking powder and baking soda. These are leavening agents, not flavor. For baking recipes, the standard rule is: scale linearly up to 3× the original recipe. Beyond that, use 2.5× the leavening even if you're tripling everything else. Over-leavened baked goods rise too fast and collapse.

Cooking time. This is where the most mistakes happen. Doubling a recipe does not double the cooking time. A roast chicken that serves 4 cooks for 90 minutes. Two roast chickens don't cook for 3 hours — they cook for about 90 minutes (in separate pans with adequate airflow). What changes is oven capacity and airflow, not time-per-unit.

Pan size. A doubled cake recipe doesn't bake correctly in two standard pans stacked — it needs the right pan-to-batter ratio. Use two pans of the original size, or the next standard size up.

Alcohol in cooking. Wines and spirits are partially for flavor, partially for liquid volume. Scale the liquid volume with the recipe; the flavor concentration will take care of itself.

Our recipe scaler handles the linear math automatically and flags the categories that need adjustment.

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