I found the difference between a heavily packed cup of flour and lightly packed cup o flour was a bit more than an ounce! This is a lot in the baking world. Go to baking tips to see how to measure flour and if you have a scale, use it. Do you know how to use the “tare” button on your scale? If not, read the directions or google it. Makes baking life easy. Your friends will thank you (for even better cookies and cakes)!