Recipe scaling calculator
Rescale every ingredient in a recipe to a different number of servings.
Fill in the fields and the result will appear here automatically.
Takes the ratio of the servings you need to the servings the recipe makes and multiplies every quantity by it. A recipe line is a name followed by a single number, so «plain white flour 500» parses correctly even with spaces in the name. The factor helps assess batch size; pan capacity still needs a separate check. Every entered quantity scales linearly, without modelling taste, fermentation, pan geometry or baking time.
How it works
Formula and logic
Factor = wanted serving equivalents ÷ original equivalents; new row amount = original × factor. Both serving values are positive and may be fractional. The last number in a line is quantity; preceding text is the name. Quantities are nonnegative. Row sums have physical meaning only with a shared unit. With mixed units, use individual rows rather than treating their sum as mass or volume.
Example
837 g for 4 servings scaled to 6 gives factor 1.5 and 1255.5 g. Target 2.5 equal serving equivalents gives factor 0.625 and 523.125 g. Those sums use a list entirely in grams; a zero-quantity ingredient remains zero.
Fields and units
- Ingredients: name and quantity per line — name; quantity in the ingredient’s original unit
- Servings in the recipe — unitless
- Servings needed — unitless
How to use
- — End each line with one quantity and retain its unit in the name or original recipe.
- — Enter positive original and wanted serving equivalents.
- — Check individual rows; use the aggregate only when units agree.
- — Check cooking time, pan and technique separately from linear scaling.
Method and limitations
- Calculation method
- Formula and logic
- Limitation
- Linear scaling preserves entered proportions but does not validate preparation technique or the altered recipe.
FAQ
Does it matter what units the ingredients are in?
Each row can retain its own unit, such as grams, mL or items. Their numerical sum is not total mass or volume; it is meaningful only when all units agree.
Can a recipe be scaled down?
Yes. If you need fewer servings than the recipe makes, the factor comes out below one and every quantity shrinks proportionally.
Why are yeast and salt scaled the same as flour?
The equation preserves entered proportions and makes no individual adjustments. Alternative dosing should come from your recipe or product instructions; it does not establish a general rule to reduce salt or yeast.
What do I do if it asks for 1.5 eggs?
If the recipe allows dividing an egg, weigh a mixed egg and use the required mass fraction. Rounding an item count changes the recipe independently and is not assessed by this model.
Does baking time scale with the quantity?
No. Quantities, rather than heat transfer, are scaled. Thickness, pan, material, temperature and composition can change cooking; proportional time multiplication does not follow from the factor.