Whilst shopping I have noticed quite a number of products having very weird measurements. for example my jar of peanut butter is 127g, but I can't spot a pattern here.

Is this just a random part of production, or is there some reasoning behind this?

5 Answers 5


Quite often, it's because a manufacturer prefers to decrease the size of a packet than to increase its price. Customers notice when the price goes up but don't tend to notice the product getting smaller.

For example, jam in the UK used to be sold in jars containing one pound, which became the equivalent 454 grams with metrication. But, more recently, that's shrunk to 400g and even 350g in some cases. Similarly, according to Wikipedia, Yorkie bars used to be 70g, which then became 64.5g, 61g, 55g and now 46g; packets of crisps that used to be 30g are now often 27g (10% smaller) or even less.

  • 10
    I used to work in the grocery industry. I can confirm this practice.
    – RubberDuck
    Aug 24, 2015 at 1:28
  • 2
    Hence the need for them to market the Yorkie as a man-sized chocolate bar with the slogan "it's not for girls." All quite ironic really. Aug 24, 2015 at 6:26
  • 10
    @steveverrill Maybe their market research indicated that girls hate it when their chocolate bars shrink. ;-) Aug 24, 2015 at 7:16
  • 1
    In parts of the EU, there were standard packaging sizes. A EU directive from 2007, I think, changed that and since 2009 in the EU, manufacturers can use any packaging size they want. Since this was in the news and all, I kept watching package sizes and noticed a lot of changes. The most "innovative" way to reduce the amount is to make a bigger packaging with less content and then print "new formula" or something like that on there. It seems not nearly enough people compare the base price of the products.
    – Josef
    Aug 25, 2015 at 7:10

While 127 is a weird number, 227 isn't - it's the grams equivalent of half a pound. In most cases where something is a weird (nonround) size in metric measurements, it's 10 fluid ounces or a quarter of a pound or something else reasonable in imperial units. Why so many 454g packages instead of 500? So the same machine can be used to make 1 lb packages (just need different labels) for the US market.

  • 8
    In the case of the peanut butter, there's decent odds that it's a factor of a consistent volume -- one chart lists peanut butter density as 272.63 gram per metric cup (250mL), so 127g is 116.45mL, which is pretty close to half a US cup. (236.588mL per US cup).
    – Joe
    Aug 23, 2015 at 21:23
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    This works both ways: packages in the US are often some random-looking number of ounces or fluid ounces that turns out to be, for example 500g or 500ml. Aug 24, 2015 at 9:04
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    @kumar_harsh I think it's actually a combination of the two. If you see a packet that's a multiple of 28.3g (and, especially, 454g and 227g), it's almost certainly because it's a whole number of ounces. If you see something that's a multiple or convenient divisor of 568ml or 473ml, it's almost certainly because it's a fraction of a pint (UK and US, respectively) or a round number of pints; correspondingly, if you see a 33.8-ounce bottle in the US, it's because it's a litre, not because they were penny-pinching a 35-ounce bottle. Aug 24, 2015 at 11:49
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    @DavidRicherby I get it. I agree to your explaination too (regarding non-metric units and values). It's my mistake to not make that clear in my previous comment. What I wanted to say was that even if the weight starts at 227g, it might come down to, say, 210g. 227g/473ml etc will be there on the first iteration of the product, but with inflation, they too, may tend to become irregular.
    – kumarharsh
    Aug 24, 2015 at 12:54
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    They don't usually just pick a random number to decrease it to, though - they pick another number that's logical, just less. 5 pound bag of flour becomes 4 pounds, not 4.543 pounds. 12 oz jar of jam becomes 10 oz. Kate's answer seems likely to be why the number is such an odd looking one - it's a normal amount, in some other measuring method.
    – Joe M
    Aug 24, 2015 at 20:09

The one thing that's not been mentioned: the size of the package needs to be something easily shipped. A standard pallet in the U.S. is 48" by 40" (not sure about Europe, but I'm sure they have a similar standard). While boxes can overhang the 40" side a bit, it shouldn't be by more than a few inches, and they certainly shouldn't overhang the 48" side, or the forklift/pallet jack won't be able to operate safely.

Say your food came in boxes 20" by 10" by 4" - so you can fit say 8 on a pallet row. This is a chocolate bar, say 4" by 2.5" by 0.5", which works out to 4oz. So you can fit 5 deep 4 across and 8 high- total of 160 bars per case. Great.

Now you want to shrink the bar by around 25% (so to around 3 oz). But a 3" by 2.5" by 0.5" bar now won't fit neatly in a 20" by 10" box - you'd have 2" extra the long way. That's bad news all around. So you make it 4" by 2" by 0.5", which fits nicely (5 deep 5 across 8 high, 200 boxes/case), but isn't quite a 25% reduction in volume per bar - so it's now 3.2oz. Well, okay, make it 0.4" high - okay, now 5x5x10 or 250 per case, fantastic, a bit more than 25% reduction though, now it's 2.56oz...

Of course you could switch box sizes, but in some case you can't really do that - either because the company is a smaller company with a more limited box size choice (and perhaps a ton of pre-printed customized boxes they don't want to toss), or because of some other restrictions. Very large items particularly have this problem. As such, sometimes sizes are chosen for volume-to-ship criteria rather than just round-number-on-box.


This will not be a direct answer to your question, but bear with me.

When a producer is choosing their packaging, they have several options. They can portion by weight or volume (or amount, but that's useful less often for produce). They can then choose whatever serving "size" they want; producers of new products may have to determine sizes by themselves, but most often there are already standardized or normalized packages out there. Either way, though, these sizes are based on a combination of how much we - the consumers - are the most comfortable with buying, but also based on average consumption. This means that different products have different preferred sizes.

Added to this, different countries use different measurements (e.g. the US's imperial system or regional trends like dozens) and, finally, what's to say that 127 g is any more random than, say, 100 g?

  • I don't know that they can truly select any serving size -- if they did, we'd see more tricks like Diet Coke's 'just one Calorie' (2 servings per can) so that more items could claim '0 grams fat' (because it's less than 0.5/grams per serving).
    – Joe
    Aug 23, 2015 at 21:26
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    The US doesn't use Imperial: they use American customary units, which they usually call "English", despite them not being English. The significant difference from a food point of view is that a US pint is only 16 fluid ounces, whereas an Imperial pint is 20 (the fluid ounce is also slightly different). Also, and this is probably only relevant if you're really hungry, a US hundredweight is 100 pounds (logical, huh?), whereas an Imperial hundredweight is 112 pounds (buuuh?), with a concommitant effect on the size of a ton (both versions are 20 hundredweight). Aug 23, 2015 at 23:52
  • 2
    the non-metrics are so incredibly painful :)
    – kumarharsh
    Aug 24, 2015 at 12:55
  • Certainly can't choose "any" serving size in the US anymore - FDA has some specific limits, and will probably have more of those in time. Many foods have specific requirements (for example, foods in a size that could reasonably be consumed in one sitting have to be labeled with that as a choice, though they can also have a specific serving recommendation with an alternate set of nutritional details).
    – Joe M
    Aug 24, 2015 at 20:31

100% marketing

When the packaged weight serves no normal recipe use, or is not a round number e.g. 1 Kg

When the price end in .99 or .95

You are a victim of marketing

Avoid these if you can, or just smile and carry on

  • 2
    How would 127g be marketing?
    – Terry
    Aug 25, 2015 at 18:11
  • By what indication do you deem the asker a victim?
    – phresnel
    Aug 26, 2015 at 9:02
  • @Terry exactly. Refer to David Richerby top answer
    – TFD
    Aug 28, 2015 at 23:36
  • @phresnel when you buy 127g of something you are most likely buying pwhat the marketer wants you to buy to maximise their profit, you are probably not buyin what you actually want
    – TFD
    Aug 28, 2015 at 23:37
  • @TFD: Probably, yes. But if you are aiming for peanut butter, it is unlikely that your intention was to buy 130g or 200g, you want to buy enough to make some creamy breads. The asker did not indicate how much he actually wanted to have; calling him "victim" may not be appropriate (but in some way, yes, we are all victims)
    – phresnel
    Aug 31, 2015 at 9:25

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