Doubling ingredients is easy; doubling a recipe is not
Scale every ingredient at once for a different serving count, and see which parts of a recipe do not scale linearly.
Multiplying ingredients is arithmetic. Scaling a recipe is not, because time and pan size do not follow the same multiplier.
A cake batter doubled needs a bigger tin or two tins, and baking time changes with depth rather than volume. Salt and strong spices also tend to need slightly less than the straight multiple.
What this calculator shows
- Every ingredient rescaled to your target servings
- The scale factor applied
- Optional rounding to amounts you can actually measure
What to keep in mind
- Ingredients scale linearly; cooking time and pan dimensions do not.
- Baking is less forgiving than cooking — leavening and salt often need a slightly lower multiple.
FAQs
Does cooking time scale with the recipe?
No. Doubling a casserole might add 20–30% to the time, not 100%. Depth and pan size drive it far more than total quantity.
Can I halve a recipe with one egg?
Beat the egg, weigh it, and use half — about 25 g. Guessing by eye is the usual source of a flat cake.
Why does salt not scale linearly?
Perceived saltiness is not proportional to concentration. Scaling up, start at 80% of the calculated amount and adjust at the end.
Does baking scale as well as cooking?
Less well. Baking depends on ratios and heat transfer through a specific depth, so large jumps often work better as two separate batches.
Worked example
Four servings to six
Input: Scale factor 1.5
Output: 200 g becomes 300 g, 2 eggs become 3
Note: Eggs land awkwardly at odd factors. Beat one and use half by weight rather than rounding up and unbalancing the mixture.