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The title may sound silly, but the question is serious:

When I buy butter, the package says Net Wt. 16oz, and I trust this because the authorities regulate such things.

Inside the package, each stick is divided evenly into 8 tablespoons. Now, although a fluid ounce of water might weigh almost exactly a 1/16 of a lb., butter is like 80% fats. There's no way a fluid ounce of butter (exactly 2 tablespoons) weighs 1/16 of a lb.

So, how many tablespoons of butter are there in a "tablespoon" (per the package marking) of butter?

9
  • Pretty sure this is just the density of butter in fl.oz./oz.
    – Him
    Oct 5 '21 at 0:16
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    1 fluid ounce of water weighs 28.4131g. 1 tablespoon of water weighs 17.7582g. I am not sure how this matches your calculations.
    – Dave
    Oct 5 '21 at 11:34
  • 1
    The only way I can make sense of this question is if the 16oz package contains 4 sticks. Is that the case, or have I misunderstood? That's not the way butter is packaged in my country. Oct 6 '21 at 1:19
  • 3
    @DawoodibnKareem the whole "stick of butter" concept is an American thing. Here it's a block of 250g with approximate 50g markings on the wrapper
    – Chris H
    Oct 6 '21 at 8:18
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    Makes sense. I've seen recipes that call for "1 stick of butter" or "1/2 stick of butter" or whatever, and had no idea how much that is. Oct 6 '21 at 20:26
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16 fluid ounces of water do not weigh one pound, they weigh a little more (about 1.05lbs), because the US fluid ounce is not based on water, unlike the liter.

You are correct that 16 weight ounces of butter aren't equivalent to 16 fluid ounces either, but they're pretty close. 1 fluid ounce of butter is 99% of one weight ounce. So if you're getting 16 weight ounces of butter, you're actually getting an extra 1% over 16 fluid ounces.

And who's going to complain about 1% extra butter?

So, your answer is approximately 1.01 tablespoons.

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  • 4
    I'm sure that this volume/weight mismatch is well within the error in most cooking implement measurements.
    – bob1
    Oct 5 '21 at 7:39
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    @bob1 especially trying to measure a bulk solid with a spoon.
    – Chris H
    Oct 5 '21 at 9:34
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    The error in the fluid ounce - weight ounce conversion (for water) and the difference in density between water and butter have opposite effects and are of similar magnitude, so they almost cancel. I'm not sure about the US, but in the EU this would all be within the allowable error for packaged foods.
    – Chris H
    Oct 5 '21 at 9:38
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    For this answer I went down the rabbit hole of "what substance IS the US fluid oz based on" and the answer seems to be "history". If there's any liquid where 1floz == 1ozwt, it's accidental.
    – FuzzyChef
    Oct 5 '21 at 17:28
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    "And who's going to complain about 1% extra butter?" Only a fool. It's like good times, and friends, hard to have too much of
    – TCooper
    Oct 5 '21 at 21:22

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