Cooking
New amount for one ingredient
Applied once per proportional ingredient. With a factor of 1.5, 250 g becomes 375 g.
The Formula
new amount = original amount x scale factor
Applied once per proportional ingredient. With a factor of 1.5, 250 g becomes 375 g.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| original amount | The quantity the recipe lists | any single unit | Works for grams, millilitres or any single unit, provided you stay in one system throughout. |
| factor | Scale factor from the first formula | dimensionless | Unitless, so multiplying never changes the unit of the answer. |
| new amount | The quantity to use at the new scale | same as the original | 375 g when 250 g is multiplied by 1.5, and 750 g when it is multiplied by 3. |
What Each Symbol Means
original amountany single unit
The quantity the recipe lists
Works for grams, millilitres or any single unit, provided you stay in one system throughout.
factordimensionless
Scale factor from the first formula
Unitless, so multiplying never changes the unit of the answer.
new amountsame as the original
The quantity to use at the new scale
375 g when 250 g is multiplied by 1.5, and 750 g when it is multiplied by 3.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to scale a recipe page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Scale A Recipe, filed under Everyday Life. Every number the guide produces comes from substituting into this one line.