Keep a half-recipe reference
Open the recipe-halving card and printable PDF for common measures, eggs and a small-batch example.
How to scale the whole ingredient list
- Paste one ingredient per line, with the quantity at the beginning.
- Choose a multiplier, or enter original and target servings. The factor is target servings divided by original servings.
- Review lines marked as uncertain. Edit their quantity and ingredient label, then select Scale only when the interpretation is right.
- Choose decimal or kitchen-fraction display. Copy or print the reviewed ingredient list.
Worked example: four servings to six
The factor is 6 ÷ 4 = 1.5. A list containing 200 g flour, 1 1/2 cups milk, ¾ tsp salt and 2–3 tbsp sugar becomes:
300 g flour 2.25 cups milk (or 2 1/4 cups) 1.125 tsp salt (or 1 1/8 tsp) 3–4.5 tbsp sugar
Both ends of a range are scaled independently. The dash stays a range separator; it is not a subtraction or an ingredient-list item number. Ingredient units and labels stay intact.
Exact calculations, practical display
Decimals and fractions are stored as exact rational numbers. For example, 0.1 is kept as 1/10. Scaling a quantity and reversing the factor therefore returns the original amount before display rounding. Each change starts from the original ingredient quantities, never from a rounded result.
Decimal display uses up to four places; kitchen display rounds to the nearest eighth. The ≈ symbol marks a rounded amount. A tiny positive amount is shown as a decimal or exact fraction instead of silently becoming zero. Fractional eggs remain fractional: 2 eggs at 1.25× gives 2.5 eggs, not an automatic three eggs.
What the parser leaves for you to review
The scaler accepts decimal numbers, plain and mixed fractions, Unicode fractions such as ½ or ¾, and quantity ranges. An ingredient without a clear leading quantity is left unchanged. Comma-separated numbers such as 1,000, pan dimensions and numbered method steps are not guessed.
Pack sizes and percentages: “2 (400 g) cans tomatoes” and “100 g 70% chocolate” are flagged. If you confirm the leading quantity, 2× gives “4 (400 g) cans tomatoes” and “200 g 70% chocolate”. The package size and cocoa percentage are preserved.
Dual measurements: “1 cup (120 g) flour” needs review because the two amounts describe the same ingredient. Pick one measurement and edit the line to “120 g flour”, or update the secondary quantity yourself before confirming. The tool does not quietly scale one measurement and claim the other still matches.
Instructions: “Bake at 180°C for 30 minutes” stays unchanged. Oven temperatures, method times and numbers inside notes are not automatically multiplied. You can deliberately edit an uncertain line, but the default is to preserve it.
Weight, volume and fractional eggs
No unit conversions or ingredient densities are inferred. A gram stays a gram and a cup stays a cup; cup conventions can differ between recipes. A kitchen scale is useful for small portions. For a fractional egg, whisk the egg and weigh the portion required by your recipe, rather than rounding to a whole egg.
King Arthur Baking’s recipe reduction guidance discusses weight-based scaling and portioning eggs. The arithmetic tool does not guarantee that any recipe scales successfully at every size.
Privacy and output
Your ingredient text is processed on your device and does not appear in the page address. Copy writes plain text to your clipboard; Print opens the browser’s print dialog with the ingredient list. No file is pretended to be a downloaded recipe. The site’s existing cookie-free analytics remain separate from the ingredient text.
If the change starts with a different pan, get the geometric factor from the pan converter. For a flour-based bread formula, use the baker’s percentage calculator instead.