Scale a recipe by servings, by a factor, or by pan size, with practical fractions, part eggs given as a weight, and the ingredients that do not scale linearly handled as such.
Change the inputs that matter to your decision. Optional assumptions stay collapsed until you need them.
One per line, the way the recipe writes them — "1 1/2 cups bread flour".
Scaling by 1.5× across 6 ingredients.
Baking powder is damped to 1.41× instead of 1.5×. Salt is damped to 1.44× — taste before adding the rest.
| 2 cups all-purpose flour | 3 cupsScales directly |
|---|---|
| 1 cup sugar | 1 1/2 cupsScales directly |
| 1 tsp baking powder | 1 3/8 tspScaled at 1.41× rather than 1.5×. Chemical leavening over-rises and then collapses when it is scaled straight up. |
| 1/2 tsp salt | 3/4 tspScaled at 1.44× rather than 1.5×, then taste. Salt and strong spices read stronger in a larger batch. |
| 2 eggs | 3 eggsCounted |
| 1/2 cup butter | 3/4 cupScales directly |
Chemical leavening and salt are damped rather than multiplied, because gas production and perceived saltiness do not rise in step with batch size. Pinches and to-taste amounts are held. Bake time follows batter depth rather than batch size, so a doubled cake in the same pan takes considerably longer than double.
Practical notes about the inputs, assumptions, and result.
Because gas production scales with the amount of leavening but the batter's ability to hold that gas does not. A doubled batch with doubled baking powder rises too fast, outruns the structure setting, and collapses in the middle. The standard bakery correction damps the increase, which is what happens here — and the tool tells you the figure it used rather than quietly changing it.
Beat a whole egg and weigh out the part you need. A large egg is about 50 g shelled, so half is 25 g. That is the only practical way, which is why a part egg is given here as a weight rather than as "1 1/2 eggs" — an instruction nobody can follow.
No, and this is the most common way a scaled recipe fails. Heat travels through the depth of the food, not its total mass. A cake batter doubled into the same pan is twice as deep and takes far longer than twice as long; the same batter spread into two pans takes roughly the original time. Scale by pan area to hold the depth and the time barely moves.
Because measuring spoons and cups step in eighths, so an exact 0.2 cup cannot be measured. Snapping to the nearest measurable amount is unavoidable, but doing it silently moves the quantity by up to a quarter — which matters for leavening and salt. Anything over 2% is reported so you can decide whether to weigh it instead.
Perceived saltiness and spice intensity do not rise in step with volume, so scaling them straight up over-seasons a large batch. They are damped when scaling up and left alone when scaling down, and the result says to taste before adding the rest. Scaling down is the safe direction: you can always add more.
If a line has no leading quantity — "zest of one lemon", "a splash of vanilla" — there is nothing to multiply, so it is carried through as written rather than dropped or guessed at. The result tells you how many lines that applied to.
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