About the Recipe Scaler
This recipe scaler multiplies every ingredient in a recipe by the ratio between the number of servings it currently makes and the number you actually want, handling whole numbers, decimals and cooking fractions like 1/2 and 1 1/2 correctly. It reads a plain list of ingredients exactly as written in a recipe, one per line, and returns a scaled version with the quantities updated and everything else — the ingredient names and any notes — left untouched.
How to use the Recipe Scaler
- 1
Paste the ingredient list, one item per line, with the quantity at the start of each line.
- 2
Enter how many servings the recipe currently makes.
- 3
Enter how many servings you actually want.
- 4
Copy the scaled ingredient list from the box at the bottom, ready to paste wherever you're cooking from.
What people use it for
Doubling a recipe for a bigger gathering
Scale every ingredient at once rather than doing the multiplication by hand for each line, especially useful with awkward fractions like 1/3 or 2/3 of a cup.
Cooking for one from a family-sized recipe
Shrink a recipe written for four or six servings down to a single portion without the arithmetic errors that come from mental maths on fractions.
Adjusting a recipe for a different pan size
Scale ingredient quantities to match a pan with a different area or volume than the recipe was originally written for.
How quantities and fractions are read and rebuilt
The tool looks for a number at the very start of each line — a plain whole number, a decimal, a simple fraction such as 1/2, or a mixed number such as 1 1/2 — and treats everything that follows as the ingredient description, carried through completely unchanged. After scaling, the result is checked against a set of common cooking fractions — eighths, quarters, thirds, halves and so on — and displayed as a fraction when it lands close to one of them, since that matches how measuring cups and spoons are actually marked, rather than showing an ugly, unmeasurable decimal like 0.667 cups.
Why some ingredients don't scale perfectly
Most ingredients — flour, sugar, liquids, most vegetables — scale in direct proportion to the number of servings, and multiplying them is mathematically exact. Leavening agents such as baking powder and baking soda, along with strong spices and salt, behave differently at large scaling ratios: doubling a cake recipe rarely needs precisely double the baking powder, and professional bakers routinely scale these more conservatively and adjust to taste. Treat the scaled figures for these specific ingredients as a strong starting point rather than a guaranteed final answer.
Tips
- Write quantities as plain numbers or fractions at the start of each line — 'a pinch of salt' or 'salt to taste' with no leading number is left unscaled, which is usually the right outcome anyway.
- For leavening agents and strong spices, scale conservatively at large ratios and adjust to taste rather than trusting the multiplier exactly.
- Double-check the scaled quantities against the measuring tools you actually own — a set without eighth-cup markings may need the nearest practical rounding.