Converte
Cooking
Each ingredient has an approximate density. Flour does not weigh what honey weighs. A US cup is 240 ml, a metric cup is 250 ml, a tablespoon is 15 ml, a teaspoon is 5 ml.
How it works
Grams are volume times grams per millilitre. Sifted wheat flour is about 0.53 g/ml. Granulated sugar is about 0.85. Butter is about 0.96, so a US cup lands near 230 g rather than a package’s tidy 227 g.
A level spoon and a heaped spoon are different. The page assumes the note printed next to the ingredient. Packing flour matters more than the third decimal.
Questions
Why is butter not 227 g per cup?
Because 240 ml × 0.96 g/ml is 230.4 g. 227 g is a slightly shorter cup used on many US packages. The gap is under a spoon.
Can I convert baking powder?
No. The density varies and the usual amount is too small for this ruler.
Why the ingredient note?
It says whether the powder is loose or the sugar is packed. Without that, the grams look more exact than they are.