Scaling a recipe

To scale a recipe, divide the yield you want by the original yield to get a conversion factor, then multiply every ingredient by that number. Working in weights makes this much easier and more accurate than cups and spoons, and baker's percentages let you rebuild a formula at any size.

Not everything scales in a straight line. Pan size changes baking time and temperature needs, eggs may need to be weighed or beaten and divided, and very large batches can overwhelm a home mixer. Leaveners, salt and spices are often adjusted slightly by taste and testing. When doubling a cake, it is usually safer to bake it in two pans than one deep one.