Recipe Scaler

The scaling factor is new servings ÷ original servings. Going from 4 to 6 servings gives 6 ÷ 4 = 1.5, so multiply every ingredient by 1.5: 2 cups of flour becomes 3, one egg becomes 1.5, and so on. Doubling is ×2, halving is ×0.5 — the same single multiplier applies to every line in the ingredient list.

Ingredients scale cleanly, but a few things do not. Cooking time barely changes for a bigger batch spread in the same pan depth — heat still has to penetrate the same thickness of food, so check for doneness with a thermometer or the usual visual cues instead of multiplying the minutes by the same factor. Seasoning (salt, spices, leavening agents like baking soda or baking powder) often needs less than the full factor too: taste and adjust rather than blindly scaling, since strong flavors and leavening reactions don't scale in a straight line the way bulk ingredients do.

Doubling a batch does not mean doubling a round pan's diameter — pan area scales with the radius squared, not linearly with the radius, so a pan twice the diameter actually holds four times the batter, not two. Doubling a recipe safely usually means keeping the same pan depth and either using two pans of the original size or one pan with roughly double the surface area (for a round pan, that is closer to 40% more diameter, not 100% more). Get the area wrong and a doubled batch either overflows a same-size pan or spreads too thin in an oversized one, throwing off both texture and bake time.

Scaling can produce fractions like 1.5 eggs or 0.75 tsp. Round to practical amounts — beat an egg and use half by volume, or measure 3/4 of a teaspoon rather than trying to split a physical teaspoon. Use the cooking measurement converter to turn odd volumes into spoons and cups you can actually measure, since "1.33 cups" is far easier to work with as "1 cup plus 5 tablespoons."

Some recipes resist simple multiplication no matter how carefully the ingredients are scaled. Yeast-raised bread is the clearest case: fermentation time depends on dough volume, temperature and yeast activity in ways that don't track a linear ingredient multiplier, so a doubled loaf doesn't rise in exactly double the ingredients-implied proportion of time. Precise candy-making (which runs on exact sugar concentrations and temperatures) and recipes tied to a specific piece of equipment — a particular pan, a specific mold, a sous-vide vessel sized for one portion — are similarly resistant, because the physical setup itself, not just the ingredient ratio, is part of what makes the recipe work.