How do I scale a recipe to a different number of servings?

Divide the servings you want by the servings the recipe makes to get a scale factor, then multiply every ingredient amount by that factor. To take a 4-serving recipe to 6, the factor is 6 ÷ 4 = 1.5, so 2 cups of flour becomes 3 cups.

Does recipe scaling work for baking?

Mostly, but with caveats. The ingredient ratios scale cleanly, yet baking is sensitive to pan size, dough/batter depth, and oven dynamics. A doubled cake batter in the same pan bakes deeper and slower; leavening (baking soda/powder) and salt can behave non-linearly at the extremes. Scale the ingredients with the factor, but adjust pan size and bake time by eye rather than by the same multiplier.

How do I scale eggs, which only come whole?

Apply the factor, then round to a whole egg. If you need precision (e.g. 1.5 eggs), beat one extra egg and measure out half by weight or volume — a large egg is roughly 50 g, so half is about 25 g. For small adjustments, rounding to the nearest whole egg is usually fine.

Does cooking or baking time scale with the recipe?

No. Time does not scale on the same factor as the ingredients. What changes the time is the depth of the food and the pan/dish you use, not the total quantity. A doubled batch spread across two pans cooks in close to the original time; the same batch piled into one pan takes longer. Check doneness with a thermometer or the usual visual cues rather than multiplying the clock.

What about salt, spices, and strongly flavoured ingredients?

Scale them with the factor as a starting point, but taste and adjust — perceived saltiness and spice heat are not strictly linear, and large scale-ups can taste over-seasoned. Add the scaled amount in stages and taste before committing the full quantity.

Why does the scaled amount sometimes show as a decimal?

The widget shows a friendly cooking fraction (1/4, 1/3, 1/2, 2/3, 3/4) when the result lands close to one. When it doesn't, it falls back to a clean rounded decimal so the number stays honest rather than forcing it into a fraction that isn't accurate.

Recipe Scaler — Resize Any Recipe by Servings

One ratio, applied to every ingredient. Friendly fractions where they fit.

Scaling a recipe is a single ratio applied uniformly to every ingredient: divide the servings you want by the servings the recipe makes, then multiply every quantity by that one number. Doubling a 4-serving recipe to 8 is a factor of ×2; halving it to 2 is ×0.5. The widget below shows the scale factor and resizes one ingredient so you can sanity-check the math — then apply the same factor to the rest of the list. Baking is the one place to be careful: the ratio handles the ingredients, but leavening behaviour, pan size, and bake time do not scale on the same line.

Enter the recipe’s original yield, the yield you want, and one ingredient amount. The same scale factor applies to every ingredient in the recipe.

Original servings

Desired servings

One ingredient amount

Scale factor

×2

8 ÷ 4 = 2

Scaled ingredient

2 × 2 = 4

Multiply each remaining ingredient by the same factor. Friendly fractions (1/4, 1/3, 1/2, 2/3, 3/4) are shown where the result lands close to one; otherwise the amount is rounded to a clean decimal.

How to use

Enter the original yield
Type how many servings the recipe currently makes into "Original servings".
Enter the yield you want
Type the number of servings you actually need into "Desired servings". The scale factor updates as you type.
Scale each ingredient
Put one ingredient amount into the last field to see it resized, then multiply every other ingredient by the same factor. Friendly fractions appear when the result lands near 1/4, 1/3, 1/2, 2/3, or 3/4.

Worked examples

Goal	Servings	Factor	2 cups becomes
Double a recipe	4 → 8	×2	4 cups
Half a recipe	4 → 2	×0.5	1 cup
Stretch to a crowd	4 → 6	×1.5	3 cups
Scale up a single serving	1 → 3	×3	6 cups

Frequently asked questions

How do I scale a recipe to a different number of servings?: Divide the servings you want by the servings the recipe makes to get a scale factor, then multiply every ingredient amount by that factor. To take a 4-serving recipe to 6, the factor is 6 ÷ 4 = 1.5, so 2 cups of flour becomes 3 cups.
Does recipe scaling work for baking?: Mostly, but with caveats. The ingredient ratios scale cleanly, yet baking is sensitive to pan size, dough/batter depth, and oven dynamics. A doubled cake batter in the same pan bakes deeper and slower; leavening (baking soda/powder) and salt can behave non-linearly at the extremes. Scale the ingredients with the factor, but adjust pan size and bake time by eye rather than by the same multiplier.
How do I scale eggs, which only come whole?: Apply the factor, then round to a whole egg. If you need precision (e.g. 1.5 eggs), beat one extra egg and measure out half by weight or volume — a large egg is roughly 50 g, so half is about 25 g. For small adjustments, rounding to the nearest whole egg is usually fine.
Does cooking or baking time scale with the recipe?: No. Time does not scale on the same factor as the ingredients. What changes the time is the depth of the food and the pan/dish you use, not the total quantity. A doubled batch spread across two pans cooks in close to the original time; the same batch piled into one pan takes longer. Check doneness with a thermometer or the usual visual cues rather than multiplying the clock.
What about salt, spices, and strongly flavoured ingredients?: Scale them with the factor as a starting point, but taste and adjust — perceived saltiness and spice heat are not strictly linear, and large scale-ups can taste over-seasoned. Add the scaled amount in stages and taste before committing the full quantity.
Why does the scaled amount sometimes show as a decimal?: The widget shows a friendly cooking fraction (1/4, 1/3, 1/2, 2/3, 3/4) when the result lands close to one. When it doesn't, it falls back to a clean rounded decimal so the number stays honest rather than forcing it into a fraction that isn't accurate.

About

Why one factor is enough

A recipe is a set of ratios. As long as you multiply every ingredient by the same number, those ratios are preserved and the dish keeps its character. That single number — desired servings divided by original servings — is the whole of the math, which is why the widget puts it front and centre.

Where the math stops and judgement starts

Scaling handles quantities, not physics. Pan size, batter depth, heat transfer, leavening reactions, and evaporation all shift when a batch grows or shrinks, and none of them follow the serving ratio. Treat the scaled quantities as exact and the bake time, pan choice, and seasoning as starting points to adjust by feel.

Rounding and fractions

Computations run in your browser on IEEE 754 doubles. The scaled amount is matched against common measuring-cup fractions within a small tolerance; anything outside that tolerance is shown as a decimal rounded to two places, so the displayed amount never overstates its own precision.

Sources & references

Authoritative references behind the math, constants, and tables on this page. Verified by Buğra Sözeri on the dates shown and re-checked at every deploy.

King Arthur Baking — How to scale a recipe — Baking authority on scaling caveats: pan size, leavening, and bake-time adjustments that do not follow the ingredient ratio(as of 2026-06-27)
ECMAScript Language Specification — Numbers — Specifies JavaScript's double-precision arithmetic that drives the scale factor and quantity math in the widget(as of 2026-06-27)