Recipe Scaler Widget
Put a recipe resizer under any recipe. Readers paste the ingredient list, say how many it serves and how many they need, and get every line rewritten: cups and spoons as readable fractions like 3 3/4, grams and millilitres as decimals, and anything without a quantity left untouched and flagged.
Live preview
Under the widget on your page: Powered by A2Z Tools
Embed code
<iframe src="https://a2z.tools/embed/w/recipe-scaler" title="Recipe Scaler by A2Z Tools" width="100%" height="760" style="border:0;width:100%" loading="lazy" allow="clipboard-write"></iframe>
A plain iframe. Works everywhere, including site builders that strip scripts. Adjust height if your content needs more room.
<div data-a2z-widget="recipe-scaler" data-height="760"></div> <script async src="https://a2z.tools/embed.js"></script>
Adds a small script (what it does) that sizes the widget to fit its content, loads it lazily and keeps it isolated from your page's CSS.
Works with
How it works
Each line is read from the left. A leading quantity can be a whole number, a decimal (1.5 or 1,5), a fraction (1/3), a mixed number (2 1/2), a Unicode fraction (1 with a half sign) or a range such as 2-3; a leading bullet is kept. The quantity is multiplied by the target servings divided by the original servings - 4 to 6 is a factor of 1.5 - or by a factor typed directly. Metric units (g, kg, ml, l, mg, cl, dl) are written back as decimals: 300 g becomes 450 g. Everything else - cups, tablespoons, teaspoons, ounces, pounds and plain counts such as eggs - is rounded to the nearest half, third, quarter or eighth when that is within 4%, so 2 1/2 cups becomes 3 3/4 cups and 1/3 tsp becomes 1/2 tsp, with cup and cups corrected. A line with no leading number, a numbered step such as "1. Preheat", or a temperature is never changed and is marked as kept.
Method
- Factor = servings wanted / servings in the recipe (or the factor entered)
- New quantity = leading quantity x factor (both ends of a range)
- Metric units: decimal, 0-3 places by size; other units: nearest 1/2, 1/3, 1/4 or 1/8 within 4%, else decimal
- Lines without a leading quantity are returned unchanged
Worked examples
Four to six servings
Inputs: 2 1/2 cups flour; 300 g sugar; 1/3 tsp salt; 1 cup milk; scale 4 -> 6
Result: 3 3/4 cups flour; 450 g sugar; 1/2 tsp salt; 1 1/2 cups milk
Factor 1.5; cup becomes cups when the amount rises above one.
Halving with a range
Inputs: 2-3 cloves garlic; Salt to taste; factor 0.5
Result: 1-1 1/2 cloves garlic; Salt to taste (kept)
The salt line has no quantity and is left unchanged.
Limitations
- Only the leading quantity is scaled; numbers later in the line, such as "(250 g)" or "a 400 g tin", are not changed.
- Does not convert to larger units - 16 tablespoons stays tablespoons rather than becoming 1 cup.
- Leavening, salt and spices sometimes need less than linear scaling in very large batches.
Where publishers use it
- A food blog's recipe card, so readers can cook for two or for twelve
- A school cookery department scaling a class recipe up for a bake sale
- A small caterer converting a family recipe to a 40-portion batch
- A meal-kit company's help page for adjusting portions
- A community cookbook website with recipes from many contributors
Questions
Which formats does it understand?
Whole numbers, decimals, fractions like 1/3, mixed numbers like 2 1/2, Unicode fractions such as the half and quarter signs, and ranges like 2-3 or 2 to 3. The quantity must start the line, optionally after a bullet.
Why are some lines marked as kept?
Lines like "Salt to taste", "Zest of 1 lemon" or section headings have no leading quantity, so there is nothing safe to multiply. They are shown exactly as written and flagged, so you can adjust them by hand rather than trusting a guess.
How are fractions rounded?
To the nearest 1/2, 1/3, 1/4 or 1/8 when that is within 4% of the exact amount - the spoon and cup sizes found in most kitchens. If none is that close, a short decimal is shown instead, for example 0.07 cups, which is a cue to switch to a smaller measure.
Does scaling change cooking time?
No, and it should not be multiplied. A double batch in a larger pan may need only slightly longer; a deeper pan needs more time at the same temperature. Baking times, temperatures and pan sizes are left to the cook.
Are eggs rounded to whole eggs?
Counts are shown as fractions, such as 1 1/2 eggs, so you can decide: beat two eggs and use three quarters, or round to the nearest whole egg where the recipe is forgiving.
Cite or recommend this tool
If you reference this tool in an article, course or documentation, these formats are ready to copy. They are optional - nothing is added to your site unless you paste it.
A2Z Tools Recipe Scaler https://a2z.tools/embed/recipe-scaler
<a href="https://a2z.tools/embed/recipe-scaler">A2Z Tools Recipe Scaler</a>
[A2Z Tools Recipe Scaler](https://a2z.tools/embed/recipe-scaler)
Recipe Scaler by A2Z Tools - https://a2z.tools/embed/recipe-scaler
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