Recipe scaler

Scaling a recipe is one multiplication per ingredient — the hard part is presenting the answer in a form you can actually measure. This tool rounds to kitchen-friendly fractions, and when a result lands somewhere awkward it steps down a unit instead: 1⅓ tablespoons becomes 4 teaspoons, which is a thing you can do with the spoons in your drawer.

new amount = original × (new servings ÷ original servings)

What to watch when scaling up

• Pan size. Doubling batter needs double the pan volume, or the bake will overflow and stay raw in the middle. Use the pan converter for the swap.
• Time and temperature. A larger, deeper mass takes longer at the same temperature, not proportionally longer. Check early and often.
• Leavening. Baking soda and powder scale linearly up to about double; beyond that they can leave a metallic taste.
• Salt and spice. Perception is not linear. Scale to about 75% and adjust at the end.
• Pan surface. Browning depends on surface area, not volume. Doubling a stew in the same pot means less evaporation and a thinner result.

Scaling down

Halving works well until you hit a single egg. A large egg is about 50 g out of shell — weigh it, beat it, and use half. Same for a single tablespoon of a strong ingredient: measure the whole thing and divide it rather than eyeballing a half-spoon.