walnut half bottom

November 10, 2008
8oz 1 cup
This may seem obvious to those familiar with weights and measures, but making such a statement has drawn looks that questioned my sanity!

The problem arises when people say "fluid ounce" and leave off "fluid"

Once my sister started dumping chopped walnuts from an 8 ounce bag into a measuring cup and found that she had almost half left. She said it should be enough since the recipe called for a cup.

I looked at the recipe and pointed out that it actually said "8 ounces", she then said that it was the same thing. I asked her why she thought walnuts weighed the same as water and she looked at me like I was nuts!

Of course, a "fluid ounce" is the volume of water that weighs 1 ounce. "Fluid ounce" is a meausrement of volume equivalent to 1/8 (.125) of a cup. So if you're speaking of actual (net) weight, the rule of "8oz = 1 cup" works only with things that have the same density as water.

You wouldn't expect a cup of marshmallows to weigh the same as a cup of BBs, and you shouldn't expect either to weigh 8 ounces! If you needed 8 ounces of marshmallows and you got one cup, you wouldn't have nearly enough. On the other hand, if you needed 8 ounces of BBs and you got a cup, you'd have way too much!

Walnut half top (not the same one)
In Association with Amazon.com
$6.95/mo? What a deal!!!!
3Dham's homepage