Recipe Scaling Calculator: Halve or Double Any Recipe
Enter how many servings the recipe makes and how many you want, then list up to six ingredients. Cup and spoon amounts are rounded to the nearest quarter.
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Formula
factor = desired servings ÷ original servings
new amount = original amount × factor
Cup, tablespoon and teaspoon amounts are then rounded to the nearest quarter (never below 0.25 when the amount is not zero). Other units keep two decimals.
Worked example
A recipe for 4 servings, scaled to 6: factor = 6 ÷ 4 = 1.5.
| Ingredient | Original | Scaled |
|---|---|---|
| Flour | 2 cup | 3 cup |
| Salt | 1 tsp | 1.5 tsp |
| Butter | 200 g | 300 g |
| Milk | 0.5 cup | 0.75 cup |
Frequently asked questions
How do I scale a recipe?
Divide the servings you want by the servings the recipe makes to get a factor, then multiply every ingredient by it. Going from 4 to 6 servings gives a factor of 1.5, so 2 cups becomes 3 cups.
How do I halve a recipe?
Enter the original servings and half of them. A recipe for 8 reduced to 4 servings has a factor of 0.5, so 1 cup becomes 0.5 cup and 3 teaspoons becomes 1.5 teaspoons.
Why are cups and spoons rounded to quarters?
Measuring cups and spoons come in quarter steps, so 0.3 cup is shown as 0.5 cup and 1.75 is kept as 1.75. A very small amount never rounds to zero; it shows as 0.25. Weights and millilitres keep two decimals.
Do baking times change when I scale a recipe?
Often yes. Seasoning and liquids scale well, but baking time, pan size and oven temperature depend on the dish, so treat the new amounts as a starting point and check doneness.