Recipe Scaling Calculator

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 tidy number — so 15 millilitres becomes a tablespoon and 2,000 grams becomes 2 kilograms.

How to use this tool

1. Set what the recipe serves and what you actually need.
2. Read the scaled column — amounts are converted to whatever unit reads best.
3. Watch the eggs. Two and a half is the honest problem with scaling anything baked.
4. 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 exactly the same ingredients and amounts.

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, 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.