Scale any recipe to a target serving count with smart unit-aware rounding.
| Ingredient | Original | Scaled |
|---|---|---|
| Add at least one ingredient with a quantity to see the scaled list. | ||
Each quantity is multiplied by target ÷ source. Output is rounded to cooking-friendly steps: grams/millilitres to the nearest 5 (under 100) or 10, cups/tbsp/tsp to common fractions (¼, ⅓, ½, ⅔, ¾, 1), ounces to one decimal, pieces to whole numbers.
Cooking and baking recipes are written for a fixed yield — "serves 4", "makes one 23-cm cake", "yields 12 muffins". Real kitchens deviate from those defaults all the time: half the family is travelling, you have eight guests instead of four, the bakery shift just sold out and needs three more batches by 6 am. Scaling the recipe means scaling each ingredient quantity by the same factor — straightforward in principle, brittle in execution. Mental math on "1 ¾ cup of flour × 2.5" tends to round badly. Decimal grams ("8.75 g of yeast") look weird on the bench. And some quantity types scale poorly: pinches, eggs, drops. This calculator does the bulk of the arithmetic and applies smart unit-aware rounding so the output reads like a real recipe rather than a spreadsheet.
Scale ratio R = target_servings / source_servings.
For each ingredient i: q'_i = q_i × R.
Smart rounding by unit family: - Mass / volume metric (g, ml): round to nearest 5 if total < 100, else nearest 10. So 87 g → 85 g; 134 g → 130 g. - Cups / tablespoons / teaspoons: round to the nearest of {¼, ⅓, ½, ⅔, ¾, 1} so the output reads "¾ cup" instead of "0.781 cup". - Ounces (oz): 1 decimal place. 3.45 oz stays. - Pieces (pcs, eggs, slices): round to integer (cooks usually scale eggs by integer count, accepting a small recipe drift).
The calculator pre-renders 12 input rows so the engagement-state replay (the project's history-replay feature) works against a stable shape; "+ Add row" and "−" controls let users add up to 12 rows total. Empty rows are skipped on output.
Set the source servings (what the recipe was written for, e.g. "Serves 4") and the target servings (what you need, e.g. "Serves 10"). The scale ratio is shown as a KPI. For each ingredient, enter the quantity, the unit (g, ml, kg, l, cup, tbsp, tsp, oz, lb, pcs, slice, pinch), and the name. The output table mirrors the input but with scaled quantities and rounded values. A warning banner appears when the ratio exceeds 3× — most home recipes degrade in texture or browning at extreme scale changes (the doubling rule of thumb).
A loaf-bread recipe for 1 loaf (8 slices), scaling to 3 loaves (R = 3):
A pancake recipe for 4, scaling to 6 (R = 1.5):
Halving (R = 0.5) of a brownie recipe with 2 eggs: 2 × 0.5 = 1 egg. Whole egg, no further math.
Egg arithmetic is approximate. Halving a 3-egg recipe gives 1.5 eggs — no clean way to bisect an egg precisely. Either beat the eggs and use half by weight (one large egg ≈ 50 g without shell), or accept the integer rounding and adjust slightly elsewhere.
Yeast and salt scale poorly past 4×. Yeast and salt are catalysts/regulators, not bulk ingredients; doubling yeast in bread gives faster fermentation but flavor suffers. Use baker's-percentage thinking instead — keep yeast at 0.3–1 % of flour weight regardless of batch size.
Pan size matters in baking. A doubled cake recipe in a single pan is a disaster — it overflows and the center is raw before the edges set. Scale by number of pans, or use an area ratio (a 23 cm round → 28 cm round needs ~ 1.48× the recipe, not 2×).
Cooking time does not scale linearly. A 6 kg roast does not take 2× the time of a 3 kg roast at the same oven temperature. Internal-temperature targets are more reliable.
Pinches, dashes, splashes. These imprecise units don't scale meaningfully past 2×. Accept that "a pinch of salt × 4" is just "a heaping pinch".
Liquid evaporation. Sauces and braises lose a fixed rate of water to evaporation regardless of volume. A scaled-up sauce reduces less in the same time, so seasoning and consistency need adjustment.
Leavening interaction. Baking soda neutralizes acid; doubling without doubling acid sources gives a soapy taste.
Spice bloom. Strong aromatics (clove, garlic) become overwhelming at large scales. Subtract 25 % when scaling above 4×.
Mass vs volume. Recipes mixing both (cup of flour + g of butter) need careful unit consistency on output. The calculator preserves your input units.
Yield rounding error compounds. Scaling 4-serving recipe to 7 produces awkward fractions across many ingredients; total yield is a touch off. Restate the goal as "recipe to fit 7 in equivalent texture", not "7 servings to the gram".