It also converts the other way, turning grams and millilitres into cups and spoons, with sensible rounding so the result is easy to measure.
How scaling works
RecipeScale reads each line of your ingredient list and looks for a quantity at the start: a whole number, a decimal, a fraction like 3/4, a mixed number like 1 1/2, a Unicode fraction like ½, or a range like 2–3. It then looks for a unit, recognising common spellings and abbreviations such as cups, c, tablespoons, tbsp, T, teaspoons, tsp, t, ounces, pounds, grams, millilitres, cloves, cans and sticks. Everything after that is the ingredient. Lines without a quantity, such as headings or “salt to taste”, are copied through unchanged.
The scale factor is simply the servings you want divided by the servings the recipe makes. Each quantity is multiplied, then rewritten so it is easy to measure. US volumes are converted to the friendliest spoon or cup: anything under a tablespoon stays in teaspoons, anything under a quarter cup is shown in tablespoons, and larger amounts in cups. Results are rounded to the nearest eighth, the smallest fraction most measuring sets include.
Converting to metric
Liquids are converted by volume, with one US cup equal to about 237 millilitres. Dry ingredients are better weighed, so when RecipeScale recognises an ingredient it converts by weight using typical reference values: 120 grams per cup of all-purpose flour, 127 for bread flour, 200 for granulated sugar, 213 for packed brown sugar, 120 for powdered sugar, 227 for butter, 85 for cocoa, 90 for rolled oats and 340 for honey. Weights depend on how the cup is filled, so treat them as a reliable starting point and adjust to your own measuring style.
Pan sizes
When you change pan size, the right factor is the ratio of the pan areas, so the batter fills the new pan to the same depth. Round pans use π × radius², square pans side², and rectangular pans length × width. Open the pan section, enter both pans in the same unit, and apply the ratio to the whole recipe. Your last recipe and settings are saved only in this browser.
Frequently asked questions
How many grams is a cup of flour?
About 120 g for all-purpose flour spooned and levelled. Scooped flour can be 140 g or more.
Why does sugar weigh more than flour?
Granulated sugar is denser, at about 200 g per cup; brown sugar packed is about 213 g.
What if an ingredient is not recognised?
It is converted by volume to millilitres, which you can still measure with a metric jug.
Is RecipeScale free?
Yes, with no sign-up.
Is my recipe saved?
Your last recipe is saved only in this browser so it is there next time. Nothing is uploaded.