Recipe Scaler

How It Works

Each ingredient line is parsed for a leading quantity — whole numbers, fractions like 1/2, mixed numbers like 1 1/2, unicode fractions like ½ and ⅓, decimals, and ranges like 2-3. The quantity is multiplied by the ratio of desired to original servings, then converted back to the nearest common fraction (⅛, ¼, ⅓, ½, ⅔, ¾…) for readability. Lines with no leading number — like "salt to taste" — are passed through unchanged.

Baking caveat: leavening agents (baking powder, baking soda, yeast) and salt don't always scale linearly. When doubling a recipe, use a little less than double the baking powder — start at 1.75× and adjust to taste. Mixing and baking times may also need adjustment when changing pan sizes.

Tips for scaling baking recipes: Egg quantities can't always be halved (use two yolks in place of one whole egg when halving), and pan dimensions scale by area rather than by volume. A recipe for a 9-inch round pan doesn't just double when you move to a 13×9 inch pan — the area increases by about 2×, but depth matters too.