Average vs Minimum Weight: How Supplements Are Filled
The two legal ways to fill a pack in the UK, how powders are actually filled, and why Make My Supps packs to the average quantity system.
1. Two ways to fill a pack
No filling process puts exactly the same weight into every pack. UK law, through the Weights and Measures (Packaged Goods) Regulations 2006, allows a packer to deal with that natural variation in one of two ways.
Minimum system
Every single pack contains at least the weight on the label. Packs can contain more than the label says, but never less.
Average system
The packs in a batch contain the labelled weight on average. Individual packs may contain a little less, within strict legal limits.
2. How the minimum system works
Under the minimum system, every single pack must contain at least the weight on the label. There is no tolerance at all: a 300g tub that contains 299.5g is short-weight, however full the rest of the batch is.
Because no filling process is perfectly accurate, the only way to guarantee every pack meets the label is to aim above it. The packer sets the target fill high enough that even the lightest pack in the run still clears the labelled weight. Everything above that line is giveaway: product the brand pays for but the customer gets for free.
The more a filling process varies, the bigger the overfill needed to stay safe.
Packs filled to the minimum system cannot carry the ℮ mark.
It suits products that are weighed individually, or packed by hand in very small numbers.
3. How the average system works
A packer using the average system must check a random sample of each batch and show that it meets three rules, known as the three packers' rules:
The contents of the packs must not be less, on average, than the weight on the label.
Only a small proportion of packs, generally no more than 2.5%, may fall below the label weight by more than the tolerable negative error (TNE).
No pack may be underweight by more than twice the TNE.
The packer also needs suitable weighing equipment, a documented checking system and records that Trading Standards can inspect. Packs filled this way may carry the ℮ mark next to the weight.
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Tolerable negative error
Labelled quantity Tolerable negative error
- 5g to 50g 9% of the quantity
- 50g to 100g 4.5g
- 100g to 200g 4.5% of the quantity
- 200g to 300g 9g
- 300g to 500g 3% of the quantity
- 500g to 1kg 15g
- 1kg to 10kg 1.5% of the quantity
Source: GOV.UK, Weights and measures: the law – packaged goods.
4. How powders are filled
Powders such as creatine, electrolytes and matcha are filled by an auger filler, not a weighing machine. An auger is a precision screw inside a funnel. Each fill turns the screw a set number of times, and each turn pushes out a set volume of powder into the tub, pouch or stick pack.
So an auger measures by volume, but the label declares weight. How much a given volume of powder weighs depends on how densely it is packed at that moment, and that changes during a run:
Settling and compaction. Powder at the bottom of the hopper is pressed down by the powder above it, so each turn of the screw carries slightly more weight than at the top.
Particle size and flow. Fine powders pack more tightly than coarse ones and can bridge or flow unevenly.
Humidity and temperature. Moisture makes powders clump and changes how they flow.
Batch to batch. Each new lot of raw material can have a slightly different density.
A real example
The certificate of analysis for our creatine shows a loose bulk density of 468g per litre and a tapped density of 790g per litre. The same volume of the same powder can weigh around two-thirds more once it has settled. That is why an auger, however accurate, delivers fill weights that vary.
This is why the average system exists. It recognises that volumetric fillers naturally vary, sets strict legal limits on that variation, and requires the packer to prove each batch meets them by check-weighing samples. To guarantee every pack under the minimum system instead, an auger would have to be set well above the label weight to cover its natural variation, and that giveaway would have to go into your price.
5. What the tolerances mean for your products
The TNE sets how far an individual pack may fall below the label weight, and only a small proportion of packs may fall below it by more than that. Here is what that means for the pack sizes we fill:
Pack TNE No more than 2.5% of packs below No pack ever below
- 5g stick pack 0.45g 4.55g 4.1g
- 30g pouch 2.7g 27.3g 24.6g
- 50g pouch 4.5g 45.5g 41g
300g tub or pouch 9g 291g 282g
900g tub 15g 885g 870g
These are the legal limits, not our targets. Every batch must still average at least the labelled weight, so lighter packs are balanced by heavier ones.
6. Why Make My Supps packs to average weight
It is the standard for packaged food
The average quantity system is the system most packaged food and supplements in the UK are filled to. Retailers, wholesalers and Trading Standards all work with it, so your products are packed to the standard the trade expects.
Your customers get the full weight on average
Every batch must, by law, contain at least the labelled weight on average, with strict limits on how far any single pack can vary. We check-weigh to make sure each batch meets all three packers' rules.
It is the right system for auger-filled powders
Our powders are filled by auger, which measures by volume. The average system is designed for exactly this kind of filling, with legal limits on variation and check-weighing to prove every batch meets them.
It keeps your prices lower
Under the minimum system, every pack has to be overfilled to make sure none falls below the label. Across a full run, that "giveaway" adds up and has to be built into the price. Packing to average weight avoids that cost, which keeps the price per unit lower for you.
Your packs can carry the ℮ mark
Only packs filled under the average system may carry the ℮ mark. It shows the product meets the average quantity rules and is recognised across the UK and Europe, which helps if you sell into Ireland or the EU.
How we control it
Packing to average weight means more checks, not fewer. Each batch is weighed against the three packers' rules on calibrated scales, and the results are recorded against your batch number so they can be shown to Trading Standards if ever needed.
7. What this means for your label
Show the weight as normal, for example 300g, at the minimum figure height (4mm for 200g to 1kg).
Add the ℮ mark next to the weight, at least 3mm tall. It is already on your label template.
Don't add "minimum" or "approx." to the weight. A plain weight with the ℮ is the correct declaration.
Questions?
Email hello@makemysupps.co.uk or message us on WhatsApp on +44 7414 129170.
This guide is general information, not legal advice. For full details, see the GOV.UK guidance on packaged goods or
contact your local Trading Standards service.
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