How to Scale a Recipe for More or Fewer Servings

Multiply every quantity by the servings you want divided by the servings the recipe states. A recipe for 4 scaled to 6 is ×1.5, so 200 g of flour becomes 300 g. Cookfolio does that part for you. What ruins dinner is everything that refuses to follow the ratio: eggs, salt, baking powder, pan size, cooking time. Those need a cook, not a calculator.

The math is the easy part

The ratio is target servings divided by original servings. A recipe for 4 with 200 g of flour becomes 500 g for 10 (×2.5). This linear rule genuinely holds for the bulk of a recipe: flour, sugar, liquids, fats, meat, vegetables, pulses.

Beyond roughly ×4 or below ×0.25, though, you are rewriting a recipe rather than scaling it, so expect to test it once before serving it to anyone.

Ingredients that refuse to divide

Eggs are the most common blocker. A large egg out of shell weighs about 50 g: roughly 18 g of yolk and 33 g of white. So when the maths asks for 2.5 eggs, beat 3 eggs and weigh out 125 g. To halve a 3-egg recipe, beat one egg and use about 25 g of it.

Rounding eggs up because it is easier is a bad idea in a cake batter: an egg is structure and liquid at once, so one extra in a small batter gives a wet, rubbery crumb. The other indivisibles work the same way: gelatin sheets (usually about 2 g each), whole spices, a vanilla pod, a 400 g tin of tomatoes, a stock cube.

One product truth worth knowing: an ingredient written with no number (“salt”, “a bay leaf”, “olive oil”) is left exactly as written when you change the servings. But “3 eggs” is multiplied like any other quantity, so 2.5 eggs will appear on screen. The app has no way of knowing an egg is indivisible: that is precisely the moment to reach for the scale.

Seasoning is tasted, not multiplied

Salt, pepper, chilli, garlic, strong spices (clove, cinnamon, cumin, cayenne), bay, anchovy, fish sauce and alcohol do not follow the ratio. When scaling up, start at roughly 60 to 75% of the strictly proportional amount, then taste and correct at the end.

Perceived intensity does not rise in step with volume, and salt is irreversible: you can always add, you can never remove. The reverse case matters too, so when halving a dish that is already mild, do not blindly halve the salt.

There is one exception, and without it this advice is wrong for bakers. In bread and any dough run on baker’s percentages, salt does scale linearly, at 1.8 to 2.2% of the flour weight. There it is a functional ingredient controlling fermentation and gluten, not a seasoning.

Treat 60 to 75% as a starting point to taste from, never as a law.

Baking: leavening and pan size

Chemical leavening does not scale linearly on large multiplications. The reference ratios are about 1 tsp of baking powder per 120 to 130 g of flour, and about 1/4 tsp of bicarbonate per 120 g of flour when an acid is present. When doubling or tripling, use roughly 75 to 85% of the strictly proportional amount and test once. Too much leavening makes a batter rise fast, over-expand and collapse, and leaves a soapy aftertaste. Yeast is not linear either: a doubled dough ferments faster in the same warm room, so watch the dough rather than the clock.

Pan size is the second trap, and it is pure geometry. The batter a round tin holds scales with the area of its base, pi × r²: 20 cm is 314 cm², 22 cm is 380 cm², 24 cm is 452 cm², 26 cm is 531 cm². Moving from 20 cm to 24 cm needs ×1.44 the batter, not “a bit more”, and 20 cm to 26 cm needs ×1.69.

To double a cake, prefer two tins of the original size over one large tin: bake time and crumb stay predictable. With a single deeper tin, drop the oven by 10 to 15 °C and extend the time, testing the centre.

Time follows the pan, not the servings

Cooking time is driven by thickness and exposed surface, not by total mass.

Stews and braises: doubling the batch does not double the simmer. It takes longer to come up to temperature, after which the simmer is close to unchanged, so check the meat rather than the clock. Roasts: two 1 kg chickens take roughly the time of one, because thickness is unchanged. Cook to core temperature.

Reduction: a sauce reduces through its exposed surface, so doubling it in the same pan gives a deeper layer over an identical surface. Reduction takes markedly longer and the sauce may finish thinner than intended. Use a wider pan, or reduce by eye.

Browning is the single most common failure when someone doubles a recipe. Twice the meat or mushrooms in the same pan drops the temperature and releases moisture faster than it can evaporate, so the food steams grey instead of browning. Cook in batches.

This is exactly why Cookfolio scales the ingredient list and deliberately leaves the times written in the steps untouched.

What the app does, and what stays your call

On a recipe, a + and - control sits next to the servings. The minimum is 1 serving, there is no upper limit, and it only appears if the recipe carries a servings number. Changing it multiplies every numeric quantity live on screen, with no rounding along the way, then shows at most 2 decimals with trailing zeros stripped, so 2.50 reads as 2.5 and 2.00 as 2. When the app is set to US units, cups and spoons read as kitchen fractions instead: ½ tsp, ⅓ cup, 1 ½ tbsp.

One limit is worth stating plainly: the change is a reading view, it does not rewrite the saved recipe. Cooking mode opens on the servings you picked. The unit follows along too: as soon as you move the servings, a quantity moves up to litres or kilograms with the Metric setting, or to cups or pounds with the US setting, once the total reaches 1 of that unit. With the Metric setting, 1000 ml is shown as 1 L and 1250 g as 1.25 kg. With the US setting, 16 tbsp is shown as 1 cup and 20 oz as 1.25 lb. At unchanged servings, a unit of your measurement system reads exactly as you typed it. The promotion only ever goes to those four units, so 500 ml never turns into 50 cl and 4 cups never turn into a quart.

The shopping list is a different path. Quantities from planned meals are scaled to the servings you chose, with no rounding along the way, then duplicates are merged by ingredient name across recipes, including across different units of the same kind: any volume with any volume (ml, cl, dl, l, tsp, tbsp, cup, fl oz, pint, quart, gallon) and any weight with any weight (g, kg, oz, lb, stick of butter). Metric and US units therefore merge too: 1 cup of milk from one recipe and 250 ml of milk from another give a single line. Each total shows with up to 2 decimals, or as kitchen fractions for cups and spoons in the US setting. Conversion only ever works volume to volume or mass to mass. Cups to grams is impossible for the app, because it depends on the density of the ingredient: our cups to grams guide has the per-ingredient tables. Units like “piece” or “pinch” are never converted. Quantities and oven temperatures show in the measurement system you pick in the settings, Metric or US (cups, oz, lb, °F). Until you pick one, the app follows your device: US on a device set to the United States, Metric everywhere else. The saved recipe never changes. US or metric units for your recipes shows what each setting displays.

In short, the app owns the arithmetic, and you own the judgement.

The checklist

1. Read the whole recipe first.
2. Check that the pan, pot and oven fit before shopping, using the surface rule.
3. Multiply the bulk ingredients.
4. Weigh eggs at about 50 g each instead of rounding them.
5. Hold seasoning at 60 to 75% and correct by tasting at the end.
6. Take 75 to 85% on chemical leavening above ×2.
7. Ignore the printed time and cook to core temperature or colour.
8. Do not crowd the pan: work in batches.

The free tier is 5 recipes and 5 lifetime imports, every source counted, so a blog or Pinterest import uses a credit like any other. Pro lifts both limits. Family covers up to 4 accounts sharing recipes, meal plan and shopping list in real time, which also makes weekly meal planning a shared job. The pricing page details both plans.

Import works from photo, PDF, Word, text, any recipe site, YouTube, TikTok, Instagram, Facebook and Pinterest, and the extraction is always shown for review before saving. That review screen is also where you correct a servings number the source got wrong, since every calculation above depends on it.