A cup of flour and a cup of honey weigh nothing alike — that is why plain volume-to-weight conversion fails in the kitchen. Pick the ingredient, and this calculator converts through its real density, the way professional bakers do.
Volume-to-weight conversion needs density (grams per millilitre). Flour is about 0.52 g/ml, honey about 1.42 g/ml — nearly three times heavier per cup.
They are standard kitchen averages for spooned, level measures. Packed flour or heaped spoons weigh more; for precision baking, weigh ingredients in grams.
The US cup of 236.588 ml, the measure used in most online recipes. Tablespoons are 14.787 ml and teaspoons 4.929 ml.