Recipe Scaling Calculator
Scaling a recipe is multiplication, and the awkward part is what the answers look like afterwards. Three teaspoons should become a tablespoon rather than staying as three; 1,500 millilitres should read as 1.5 litres. This scales every amount and then re-expresses each one in whichever unit is tidiest — with the displayed amount checked against what the multiplication gave: exact in a tidy unit, and otherwise to the nearest tenth of a gram or millilitre, or hundredth below ten.
What this generator does
Multiplies every ingredient by the ratio between the servings you have and the servings you want, then re-expresses each amount in the largest unit that leaves a whole number or a quarter — so 15 millilitres becomes a tablespoon and 2,000 grams becomes 2 kilograms. Spoons stop where a cook would stop using them: from four tablespoons or three teaspoons up, the amount stays in millilitres.
How to use this tool
- Set what the recipe serves and what you actually need.
- Read the scaled column — amounts are converted to whatever unit reads best.
- If eggs are in the table, watch them. Two and a half is the honest problem with scaling anything baked.
- Remember that cooking times do not scale the way quantities do.
Understanding the controls
- Recipe serves
- What the original recipe makes, between 1 and 24.
- You need
- How many you are actually cooking for. Larger than the original scales up, smaller scales down — both work the same way.
- How many ingredients
- Between 3 and 9 ingredients drawn from a plausible baking and cooking list.
- Seed
- Any word reproduces the same ingredients and amounts unless this tool has changed since.
Common use cases
- Cooking for a different number of people than the recipe assumes
- Halving a recipe without ending up with awkward fractions
- Batch cooking from a single-portion recipe
- Teaching ratio and proportion with something immediately useful
- Setting the same worked example twice from a seed
How this generator works
Every amount is converted to a single base unit — millilitres for volumes, grams for weights — before scaling, so the multiplication happens on comparable numbers. Choosing a tidier unit afterwards is presentation only, and the check confirms it: the displayed amount converted back must equal the scaled quantity in a tidy unit, and be within its printed rounding where it stays in grams or millilitres, so re-expressing an amount can never quietly change it.
Randomness and fairness
The ingredients and their starting amounts are random; the scaling itself is exact arithmetic. A seed reproduces the same recipe exactly and is therefore explicitly not cryptographically secure. Without a seed the browser's cryptographically secure generator is used.
For how randomness is produced across the whole site, see how Generate Random works.
Limitations and good to know
- Ingredients come from a built-in list rather than a recipe you paste in.
- Eggs and other whole items scale to fractions, which is mathematically right and practically useless — the tool does not pretend otherwise.
- Cooking times, tin sizes and oven temperatures do not scale with quantity and are not adjusted.
- Metric units only; cups are included but American and metric cups differ.
- Recipes are not stored between visits; seed one you want again.
Privacy and your data
The scaling is computed in your browser. Nothing about the recipe or your seed is transmitted or kept.
Related generators
- Unit Price ComparatorCompares pack sizes on price per unit and names the genuine best value, which is not always the biggest pack.
- Mocktail Recipe GeneratorA non-alcoholic drink name and, on half the draws, a line of technique.
- Smoothie Recipe GeneratorA smoothie combination idea worth trying at home.
- Potluck Coverage PlannerAssigns each guest one dish so every course is covered, and when that is impossible names the courses that ran out of cooks.