This recipe scaler calculator resizes recipes: enter the original and target servings, list your ingredients, and every quantity rescales by the exact factor — doubling, halving or anything in between.
| Ingredient | Original | Scaled |
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How Recipe Scaling Works (and Where It Doesn’t)
The arithmetic is one multiplication: factor = target servings ÷ original servings, applied to every quantity. Scaling 8 → 12 servings is ×1.5: 240 g flour becomes 360 g, 2 cups sugar becomes 3, 3 eggs become 4.5 (beat the half egg with a fork and use half, or round with judgment — eggs are the famous non-scalable). Then the caveats, which are the actual cooking knowledge:
- Leavening and salt scale nearly linearly, but at extreme factors (×4+) baking soda/powder often needs a small trim (about −10–25% at quadruple scale) or the taste turns soapy/metallic.
- Spices and extracts scale sub-linearly for most palates — start at ~75% of the linear amount for big scale-ups and adjust.
- Cooking time does NOT scale with servings. It scales with thickness and pan geometry: double batter in the same pan gets thicker and needs much longer; split across two pans and time barely changes. Temperature stays the same.
- Evaporation punishes scale-downs of soups and sauces (same surface, less volume = relatively more loss); add a splash of water when halving.
Part of our Food Calculators collection; convert the scaled volumes to grams with the Cups to Grams Converter.
Worked Example (Verified)
- Recipe serves 8, you need 12 → factor ×1.5
- Flour 240 g → 360 g; Sugar 2 cups → 3 cups; Eggs 3 → 4.5
- Halving (8 → 4, factor ×0.5): 240 g → 120 g; 2 cups → 1 cup; 3 eggs → 1.5
Pan and Batch Strategy
- Scaling up baked goods: prefer more pans over deeper batter; depth is the variable ovens care about.
- A ×1.5 cake in the same round pan fits a pan one size up (8″ → 9″) — the areas scale about right; check with the Baking Pan Converter.
- For yeast doughs, scaling is exact and safe (baker’s percentages exist precisely because dough scales perfectly) — see the Pizza Dough Calculator for the percentage method.
Related Tools
- Cups to Grams Converter
- Baking Pan Converter — matching pan size to the new batch
- Food Calculators — the full collection
Frequently Asked Questions
How do I scale a recipe up or down?
Divide the target servings by the original servings for the factor, then multiply every ingredient by it. 8 → 12 servings means ×1.5 on everything.
How do I halve a recipe?
Multiply every quantity by 0.5. Fractions get awkward at the half-egg level — beat one egg and use half by weight (about 25 g) or volume (1½ tablespoons).
Does cooking time change when I double a recipe?
Time depends on thickness, not total amount. Two pans of the original depth: nearly the same time. One pan twice as deep: substantially longer (and risk of a raw middle) — increase time in ~25% increments and test doneness early.
Should baking powder and soda scale exactly?
Nearly — for factors up to about ×2, exact scaling is fine. For very large batches, leaveners and salt are commonly trimmed slightly; taste and test govern.
Can I scale a recipe by weight instead of servings?
Yes — the factor is any ratio you like: desired total dough ÷ recipe total dough works exactly the same way (that is the Pizza Dough Calculator’s baker’s-percentage method).
Is this recipe scaler free?
Yes — free, unlimited ingredients, no sign-up.