How to Scale a Recipe Up or Down Without Ruining It
Scaling a recipe sounds like simple multiplication — and mostly it is. The scale factor is your target yield divided by the recipe's yield: doubling a 4-serving recipe to 8 means multiplying every ingredient by 2; taking a 12-cookie batch down to 8 cookies means multiplying by ⅔. This recipe scaler applies the factor to your whole ingredient list at once, understands mixed numbers ("2 1/2"), unicode fractions ("¾"), and decimals, and rewrites the result using fractions you can actually measure.
The hard parts are the edge cases, and the tool handles those too. Fractional eggs get flagged with a practical fix. Lines with no quantity ("pinch of salt") pass through untouched. And scaling beyond 3× triggers a warning, because salt, spices, and leavening shouldn't be scaled fully linearly at large multiples — professional bakers scale those to about three-quarters of the math and adjust by taste.
Common scale factors at a glance
| You want to… | Factor | 1 cup becomes |
|---|---|---|
| Halve a recipe | × 0.5 | ½ cup |
| Take 12 servings down to 8 | × 0.667 | ⅔ cup |
| Take 4 servings to 6 (or 8 to 12) | × 1.5 | 1½ cups |
| Double it | × 2 | 2 cups |
| Take 4 servings to 10 | × 2.5 | 2½ cups |
| Triple it (watch salt & spices) | × 3 | 3 cups |
One thing multiplication can't fix: geometry. If you double a cake recipe but keep the same pan, the batter sits twice as deep and will not bake in the same time. When your scaling changes pans, use our cake pan converter to get the right pan size, temperature, and timing together. And if you'd rather scale by weight — the more reliable way — convert your cups to grams first and multiply the gram figures.