Double a recipe
Doubling a recipe means multiplying every ingredient amount by 2, the same as scaling from 4 servings to 8. Fractions are where mistakes happen, so this example runs a short list through the scaler and keeps every result as an exact fraction.
Worked example
Original servings: 4 → Target servings: 8
Multiplier 2×
| Ingredient | Original | Scaled |
|---|---|---|
| Flour | 3/4 cup | 1 1/2 cup1.5 |
| Baking powder | 1 1/2 tsp | 3 tsp |
| Milk | 2/3 cup | 1 1/3 cup≈ 1.333 |
| Eggs | 1 | 2 |
Doubling 3/4 cup gives six quarters, which the scaler reduces and writes as the mixed number 1 1/2. 2/3 cup becomes 1 1/3 cup; its decimal preview, ≈ 1.333, is rounded, but the fraction is exact. Whole amounts stay whole: 1 1/2 tsp becomes 3 tsp and 1 egg becomes 2.
How the scaler handles it
- Multiplier = target servings ÷ original servings. Doubling 4 servings to 8 gives 8 ÷ 4 = 2; entering 1 and 2 gives the same result.
- Every quantity is multiplied with exact fraction arithmetic and reduced to lowest terms. Results of 1 or more are written as mixed numbers such as 1 1/2.
- When a result is not a whole number, a decimal preview rounded half up to three places is shown below it; ≈ marks a rounded value.
- Unit labels are kept exactly as typed. The scaler does not pluralize them or convert, for example, 4 tbsp into 1/4 cup.
- Cooking time, oven temperature and pan size are not doubled. A double batch usually needs a larger pan or two pans, so check the original recipe.