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Recipe Scaling Calculator — Double, Triple or Halve Any Recipe | Calcgator

Recipe Scaling Calculator

Double, triple, halve or scale any recipe to any serving size instantly. Add your ingredients, choose your scale, and get smart fraction results with baking-specific tips — no maths required.

⚡ Instant results ½ Smart fractions 🧁 Baking tips included 🖨️ Print-ready
Scale ×2 Serves 4 → 8
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Recipe Scaling Calculator
Double, triple, halve or scale to any serving size
Scale factor: ×2.00
4 ingredients
Amount Unit Ingredient
Recipe
Scaled to 8 servings
×2
Ingredient Original Scaled Amount

How to scale recipes correctly

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Desired ÷ Original = Factor

The Recipe Conversion Factor

The conversion factor is simply desired servings ÷ original servings. If a recipe serves 4 and you need 10, the factor is 2.5. Multiply every ingredient by this number. Our calculator handles the maths — and converts decimal results to the nearest practical kitchen fraction (½, ⅓, ¼, ⅔, ¾, ⅛) so you don't need to measure 0.375 cups.

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Never double exactly

Baking Rules When Doubling

Most ingredients double cleanly — but baking powder, baking soda, yeast and salt should be scaled at roughly 1.75× when doubling (not exactly 2×). Too much leavening causes an overly rapid rise that then collapses. Strong spices and vanilla extract should also be held back to about 1.5× and adjusted by taste. Our calculator flags these ingredients automatically.

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Time ≠ scale factor

Cook Time Does Not Scale Linearly

When you double a recipe, cooking time does not double. Keep the same oven temperature. If baking in the same pan, expect around 25–50% extra time. If splitting between two pans, cooking time stays roughly the same as the original. For stovetop recipes, a larger pot means longer time to reach boiling — factor this in when meal planning.

FAQ

Questions about scaling recipes

Everything you need to know about doubling, halving and scaling recipes — answered below.

💬 Ask us anything
To double a recipe, multiply every ingredient by 2. Enter your ingredients into the recipe scaling calculator above, click the ×2 quick button (or set Original Servings to 4 and Desired Servings to 8), and click Scale Recipe. The calculator handles fractions automatically — ¾ cup becomes 1½ cups, ⅓ cup becomes ⅔ cup, and so on. Note: baking powder, baking soda and salt should be multiplied by 1.75× rather than exactly 2×.
Not proportionally. When doubling most recipes, cooking time typically increases by only 25–50%, not 100%. Keep the same oven temperature. If you split the doubled batch between two pans of the same size as the original, time stays roughly the same. If baking in one larger pan, add 25–30 minutes and check for doneness using a toothpick or thermometer rather than relying on time alone.
No. When doubling a recipe, use approximately 1.75× the amount of baking powder, baking soda or yeast rather than exactly 2×. Too much leavening agent causes baked goods to rise too rapidly and then collapse, resulting in a dense, gummy texture. The same principle applies to salt (1.75×) and strong spices like chilli powder or vanilla extract (1.5×) — add conservatively and adjust to taste.
Click the ½× quick button, or set your desired servings to half the original number. The calculator divides every ingredient by 2 and converts to the nearest practical fraction. The trickiest part of halving is eggs — when you get 1.5 eggs, the calculator flags this. The solution: crack a whole egg, whisk it, then measure approximately 25ml (half a medium egg) by weight or volume.
The recipe conversion factor is: Desired servings ÷ Original servings. Multiply every ingredient by this number to scale the recipe. For example, to scale from 4 servings to 10, the factor is 10÷4 = 2.5. To scale from 12 to 4, the factor is 4÷12 = 0.333 (one-third). Our calculator computes this automatically and applies smart fraction rounding so your measurements are practical to use in the kitchen.
Yes — enter any number in the "Desired servings" field. The calculator computes the exact multiplier and scales every ingredient precisely. For example, scaling from 6 servings to 9 gives a factor of 1.5, so 2 cups of flour becomes 3 cups. Results are rounded to the nearest common kitchen fraction (⅛, ¼, ⅓, ½, ⅔, ¾) so the measurements are practical to use without decimal arithmetic.