Recipe Conversion Calculator
Enter how many portions the recipe makes and how many you need, and optionally the portion sizes, to get the recipe conversion factor and every ingredient scaled to the new batch, with amounts shown in units you can measure.
Your recipe
Leave both portion sizes blank to scale by portions only. If you enter them, use the same unit for both.
| Ingredient | Amount | Unit | Remove |
|---|---|---|---|
Scaled recipe
Enter the portions and at least one ingredient to see the scaled recipe.
A recipe conversion factor is the number you multiply every ingredient by to change a recipe’s yield: new yield ÷ old yield. To go from 10 portions to 35, the factor is 3.5; to go from 10 portions of 8 oz to 35 portions of 6 oz, it is (35 × 6) ÷ (10 × 8) = 2.625.
Recipe conversion formulas
- Conversion factor: new yield ÷ old yield.
- With portion sizes: (new portions × new portion size) ÷ (old portions × old portion size).
- New amount: old amount × conversion factor.
- Kitchen units: 3 tsp = 1 tbsp, 16 tbsp = 1 cup, 4 cups = 1 qt, 4 qt = 1 gal, 16 oz = 1 lb.
How to scale a recipe
- Find the old yield. How many portions the recipe makes, and the portion size if it is changing.
- Decide the new yield. The portions you need, at the new portion size if there is one.
- Work out the factor. Divide the new total yield by the old one.
- Multiply and convert. Multiply every ingredient by the factor, then turn the amounts into units you can measure.
Worked example
A soup makes 10 portions and you need 35, so the factor is 35 ÷ 10 = 3.5. 4 lb of onions becomes 14 lb, 2 quarts of stock becomes 7 quarts (1.75 gallons) and 2 tablespoons of salt becomes 7 tablespoons, a little under half a cup. If the portion also drops from 8 oz to 6 oz, the factor is (35 × 6) ÷ (10 × 8) = 2.625 instead.
What does not scale in a straight line
- Salt, spices and other strong flavors: scale them by the factor, but hold back a little and add the rest to taste, because a large batch is harder to correct once it is too salty or too hot.
- Baking: leavening, eggs and thickeners can behave differently in a much bigger or smaller batch, so test a batch before you scale a baked recipe by a large factor.
- Cooking time depends on the size and depth of the food and the pan, not on the size of the batch. Check doneness instead of multiplying the time.
- Equipment: make sure the scaled batch fits your pots, mixers and ovens. Two batches are often better than one overfilled pot.
Recipe conversion FAQ
What is a recipe conversion factor?
The number you multiply every ingredient by to change a recipe’s yield: new yield ÷ old yield. Going from 10 to 35 portions gives a factor of 3.5.
How do you convert a recipe when the portion size changes?
Multiply portions by portion size for both the old and the new recipe, then divide: (new portions × new size) ÷ (old portions × old size). 35 portions of 6 oz from a recipe for 10 portions of 8 oz gives 2.625.
How do you halve a recipe?
Use a factor of 0.5 and multiply every ingredient by it. Small amounts such as eggs and spices may need rounding.
Do you double the cooking time when you double a recipe?
No. Cooking time depends on the size and depth of the food, not on the batch. Check for doneness with a thermometer or by eye instead of multiplying the time.
Can I scale by weight instead of volume?
Yes, and weight is more accurate for dry ingredients. Enter each ingredient in grams or ounces and the calculator scales it the same way.
Is this recipe conversion calculator free?
Yes. It needs no sign-up, and the numbers you enter stay in your browser.
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