Recipe Scaler
Doubling a recipe is easy until the amounts stop being whole. Three quarters of a cup becomes nine eighths, and the usual approach — rounding each line as you go — quietly changes the recipe, because the ratios between the ingredients no longer hold. Here the scaling stays exact and only the printed amount is rounded, so the proportions survive even where the numbers get awkward.
What this generator does
Reads the amount, unit and ingredient from each line, multiplies every amount by the same factor, and prints each one rounded to something you can actually measure.
How to use this tool
- Paste the ingredients, one per line, with the amounts as they are written.
- Say how many the recipe serves and how many you need.
- Read the scaled list, or use the halve and double buttons.
- Lines without an amount — a pinch, to taste — are left exactly as they were.
Understanding the controls
- Ingredients
- One per line. Amounts may be whole numbers, decimals, fractions like 1/2, mixed numbers like 1 1/2, or the single characters ½ and ¾.
- Written for and you want
- The servings the recipe is written for and the number you need. The factor is simply one divided by the other, shown so you can see it.
Common use cases
- Cooking for six from a recipe written for four
- Halving a cake recipe for a smaller tin
- Scaling a recipe up for a party without losing the balance
- Working out a shopping list for a batch cook
- Converting a family recipe to a different number of portions
How this generator works
The exact scaled amount is kept alongside the printed one, and the checks look at the exact figures rather than the text — checking the printed amounts would be checking the rounding rather than the scaling. Two things are confirmed: every amount moved by exactly the same factor, and every pair of ingredients holds the same ratio to each other as it did before.
Randomness and fairness
Nothing is random. The same ingredients and servings always give the same result.
For how randomness is produced across the whole site, see how Generate Random works.
Limitations and good to know
- Amounts are rounded to eighths for small quantities and to whole numbers for weights, so a scaled recipe is not exact on the page even though the arithmetic behind it is.
- Units are not converted: grams stay grams and cups stay cups.
- Cooking times, tin sizes and oven temperatures do not scale with the ingredients, and none of them is adjusted here.
- An ingredient written without a number is left alone, which is usually right for a pinch and wrong for an egg.
Privacy and your data
Your recipe stays in your browser. Nothing you paste is transmitted or stored.
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