Scale a recipe to any number of servings: each ingredient is multiplied by new ÷ original servings, with cups and spoons shown as kitchen fractions.
更新于 已验证的示例：5
Every amount is multiplied by 1.5 to go from 4 to 6 servings; 6 of 6 lines had an amount to scale.
| Ingredient | Original | Scaled | 精确 |
|---|---|---|---|
| cups flour | 2 | 3 | 3 |
| tsp salt | 1 1/2 | 2 1/4 | 2.25 |
| cup sugar | 3/4 | 1 1/8 | 1.125 |
| eggs | 2 | 3 | 3 |
| cup milk | 1/3 | 1/2 | 0.5 |
| g butter | 250 | 375 | 375 |
Shown as 3.
Cups, spoons and counts are rounded to the nearest kitchen fraction (eighths, quarters, thirds, halves); ≈ marks a rounded value. Grams, kilograms, millilitres and litres are shown as decimals to 2 places.
Every amount is multiplied by the scale factor: the servings you need divided by the servings the recipe makes. Cup, spoon and count amounts are rounded to the nearest measure a kitchen set holds (eighths, quarters, thirds and halves) and marked ≈ when rounded. Grams, kilograms, millilitres and litres stay as decimals.
The default recipe goes from 4 to 6 servings, a factor of 1.5, so 3/4 cup of sugar becomes 1 1/8 cups and 250 g of butter becomes 375 g. The Institute of Child Nutrition teaches the same two steps for school kitchens: 35 servings from a 25-serving recipe is a factor of 1.4, which turns 3 cups of tomatoes into 4.2 cups, rounded to 4 1/4.
Lines without a number, such as "salt to taste", are kept as written. Baking time, pan size and seasoning do not scale in proportion, so check them separately.
核验来源：Python fractions: 2×3/2 = 3, 3/2×3/2 = 9/4, 3/4×3/2 = 9/8, 1/3×3/2 = 1/2, 250×3/2 = 375
核验来源：Python fractions: each amount × 1/2
核验来源：Python fractions: 3/2×5/6 = 5/4; 2×5/6 = 5/3, 3×5/6 = 5/2; 5/6 = 0.833 is nearest 7/8 among eighths and thirds
核验来源：Institute of Child Nutrition, Adjusting Standardized Recipes: 35 ÷ 25 = 1.4; 3 cups × 1.4 = 4.2 cups, rounded to 4 ¼ cups
Divide the servings you need by the servings the recipe makes, then multiply every ingredient by that factor. Going from 4 to 6 servings is a factor of 1.5, so 2 cups of flour becomes 3 cups; going from 4 to 2 is 0.5. The Institute of Child Nutrition advises converting mixed amounts such as 1 lb 8 oz to one unit (1.5 lb) before multiplying.
Half of 1/3 cup is 1/6 cup: 2 tablespoons plus 2 teaspoons, because a US cup holds 16 tablespoons and a tablespoon holds 3 teaspoons. Half of 3/4 cup is 3/8 cup, or 6 tablespoons. When no standard measure matches, the calculator shows the nearest eighth or third with ≈ and gives the exact decimal in the table.
Often, because baking time depends on the depth of the batter more than on its amount. Doubled batter in the same pan is twice as deep and needs longer; spread over a pan with twice the area, it keeps its depth and bakes in close to the original time. Keep the oven temperature the same and test for doneness early.
No. A US customary cup is 8 US fluid ounces, 236.6 mL, while the metric cup used in Australia and New Zealand is 250 mL, about 6% larger. Scaling works the same in both systems because every amount is multiplied by the same factor. NIST advises weighing ingredients on a kitchen scale for accuracy rather than measuring by volume.
准确性取决于输入值和方法的假设。十进制运算使用50位有效数字，但估算、数值方法和源数据的精度可能较低；显示时的舍入并不能消除这些限制。 已按独立来源核验的计算示例：5。 例如，“Default recipe from 4 to 6 servings”根据Python fractions: 2×3/2 = 3, 3/2×3/2 = 9/4, 3/4×3/2 = 9/8, 1/3×3/2 = 1/2, 250×3/2 = 375进行核验。
Institute of Child Nutrition — Adjusting standardized recipes (factor = new yield ÷ old yield); NIST Metric Kitchen — Culinary measurement tips.
此计算器包含 5 个已解示例，答案来自独立来源。这些示例会在测试套件中运行，你也可以在此运行验证。
Convert oven temperatures between °C, °F, fan oven and gas mark, and work out how much to scale a recipe for a different round, square or rectangular pan.
Unit price calculator: compare up to four pack sizes by price per kg, litre, 100 g, ounce or item to see which is cheapest and by how much.