How to Scale a Recipe Up or Down
Scaling a recipe means adjusting ingredient quantities to make more or fewer servings while keeping the ratios the same. The method is simple: divide the desired serving count by the original serving count to get a scaling factor, then multiply every ingredient by that factor. Cooking is forgiving of scaling — baking is less so, and a few ingredients (salt, spices, leavening) need special attention.
Last updated: March 31, 2026
The Formula
Scaling Factor = Desired Servings / Original Servings New Ingredient Amount = Original Amount × Scaling Factor
Variable Definitions
| Symbol | Name | Description |
|---|---|---|
| SF | Scaling Factor | The ratio by which all ingredients are multiplied — SF > 1 scales up, SF < 1 scales down |
| Original | Original Amount | The quantity of each ingredient in the base recipe |
Step-by-Step Example
A cookie recipe serves 24 and calls for 2 cups flour, 1 cup sugar, ½ cup butter, and 1 tsp baking soda. Scale it to serve 60.
Given
Solution
- 1Calculate scaling factor:
SF = 60 / 24 = 2.5 - 2Scale flour:
2 cups × 2.5 = 5 cups - 3Scale sugar:
1 cup × 2.5 = 2.5 cups - 4Scale butter:
½ cup × 2.5 = 1.25 cups - 5Scale baking soda (apply 75% rule for leavening):
1 tsp × 2.5 × 0.75 ≈ 1.9 tsp (use 2 tsp)
Scaled recipe for 60: 5 cups flour, 2.5 cups sugar, 1.25 cups butter, 2 tsp baking soda.
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Common Mistakes to Avoid
Scaling salt and spices 1:1 for large batches — flavours concentrate non-linearly; scale to about 75% and adjust to taste.
Scaling baking time proportionally — cooking time depends on thickness and temperature, not batch size. Use the same time and check doneness.
Not adjusting pan size — doubling a recipe in the same pan increases depth, which changes cooking time and texture.
Scaling eggs — when the scaled amount is a fraction (1.5 eggs), round to the nearest whole egg or use one whole egg plus one yolk.