How much is a cup??

Hi all

Not sure if this is the correct thread to post on but here goes.

I often see in the food lists, calorific values for a cup of something.  For example a cup of pasta is 197 cals. 

So my question is:  Just how much is a cup?  I have many cups in my home and they are all different sizes!

A set of dry measuring cups is something you should invest in! They're pretty cheap and can be found at grocery stores, even dollar stores, haha. That way you won't be guessing!

EDIT: Just noticed you're from England, so ignore the bit about dollar stores, heh. I'm unsure what measuring system you use over there, it's not all metric, you use the imperial in some cases too right? (It was developed there after all... and weight being in stones and such...) Don't mind my confusion.

Good question.

I would use a measuring cup though. But then I would have to ask, how much pasta in my measuring cup is a full cup? Do I have to pack it in so there is no more room left in the cup? Do I chop the top of the pasta off so it's level with said cup?

Seriously, I don't know!

Also depends on if the cals are for cooked or uncooked pasta. I would say that pasta has to be loosely packed, as in not stuffed in, just put in there as it would sit in the cup naturally. Also probably as close to level as possible. A few noodles or whatnot sticking up over the top probably won't add that many more calories, but 1 cup does not equal 1 heaping cup.

1 cup in the US is 2.5 dl, in Canada its 2.4 dl - not a big difference.

2.5 dl is 8.79 ounces (UK). Hope that helps.  Check out this:

http://www.onlineconversion.com/

When I look up the calorific values of say pasta or rice, it doesn't actually say whether or not it's a dry/uncooked weight. 

I can easily work out how to measure given the help from Lambea but I need to understand if it's cooked or uncooked weight!!

Thanks again

invest in an inexpensive but accurate food scale. you won't have to guess about packing food down in a cup and you'll have the most accurate of accurate readings. The food information on the box of pasta or rice is for the uncooked weight. If you measure it out on a scale first, you can be sure not to go over your allotted measure. It works well for me!

I really don't get how you can use an online conversion tool for translating cup measurements to something else... For instance, a cup full of special K is going to way less than a cup of something heavy (escapes my mind).  I would just go by the packages of your food... I'm from England but invested in a measuring cup set when i was in the dollar tree store (What a boring souvenir... useful though). 

I have a really good set of electronic scales which measure in either ounces or gramms.

The problem is that on the food lists, the nutritional value is normally for a cup of rice but it doesn't state whether or not it's cooked weight!!  Same with pasta and probably other items I've not yet looked up.

I'm happy to weigh the food and then transfer it to a cup so I will know how much I can have without having to get the scales out every time but I need to know if it's cooked or uncooked weight it's referring to.

Thanks

My assumption is that it is cooked weight, unless otherwise stated.  Since for instance, a 1/2 cup of rice uncooked would be way more than a serving once it's been cooked.  Same with pasta. 

Food Freak, the reason people are talking about weight is that in the US the label gives you the serving size in cups/spoons and in grams.  Don't know if that's the case there, but the online database is to US standard.

Thanks Joe (I know)... but you forget Mrs R is a fellow Brit! So I was just talking about conversion websites generally... it can't apply across all ingredients... you would need a conversion per ingredient (if u see what I mean)

I agree about using a scale to measure things.  I originally bought mine for the far more precise and accurate measuring it allows for in baking, but I use it for virtually all portioning at home now as well. :)  I don't know about in the UK but here in the US, weights on nutrition labels are almost always for how the food comes packaged - i.e., uncooked weights.

In pasta's case, a serving size is typically on the order of 2 oz, or ~56.7 g for a ~200 calorie portion (whether or not one agrees that this is a realistic serving size is another matter ;) ).  Assuming that we're talking about starting with dry pasta, the cooked weight would be much higher due to water absorption, so common sense should actually apply here.  After all, almost everyone here should know that carbs and protein are 4 calories per gram and that dry pasta is mostly carbs and a little protein, with very little fat and of course almost no water, so one should expect that the number of calories should be vaguely on the order of 4x its weight in grams (in practice in pasta's case it actually works out to more like 3.5x, but that's still a much higher number than it would be for cooked pasta).

I think everyone is confusing everyone else, and a quick trip back to high school physics might be enlightening.

You can't equate weight and volume.  It simply isn't possible.  An imperial "cup" is a measure of volume.  It is equivalent to 236 milliliters (mL). 

A gram is a measure of weight.  1 ounce of weight is equivalent to 28.3 grams.

Without knowing the density of the substance, you cannot convert between these two.  The easiest way to measure weight is to use a scale.  The easiest way to measure volume is to use measuring cups.

A measure of volume by cups of a dry food usually implies "lightly packed" and includes the space occupied by the air between the pieces of food.  For example, if you are measuring 1 cup of pasta (i.e. 236 mL of pasta), fill the measuring cup to the top, tap it down (don't push the noodles in, just lift the cup up and down and tap it on the counter) and then fill until it's roughly even with the top of the measuring cup.  If you are refering to a US nutritional label, this always refers to weight and calorie content AS PACKAGED.  If it's dry in the package, a serving is dry.  If it's wet in the package, a serving is wet.  This is why popcorn nutrition labels include "unpopped."  The FDA requires listing nutrition content as the food exists sitting in its package.  Some manufacturers include nutrition info for cooked as well as packaged, but this is not required, and done as a convenience to the consumer.  A very select few only include cooked weight, but this is unusual and will specify so on the package.

ALSO BE AWARE that there are two kinds of ounces - ounces and fluid ounces.  An "ounce" is a measure of weight.  A "fluid ounce" is a measure of volume (equal to 2 tablespoons).  One previous poster said:
"1 cup in the US is 2.5 dl, in Canada its 2.4 dl - not a big difference.  2.5 dl is 8.79 ounces (UK)"

These are FLUID ounces, not weight ounces.  Be careful which you are using.

Also, the easiest way to convert anything is using Google.  Try it yourself.  Google search for:
1 cup in fluid ounces
1 deciliter in cups
1 gram in pounds

Usually they give you the uncooked weight, which explains why it sometimes seems like a ridiculous number of calories packed into that quarter cup of brown rice.