Weights and measures: the law
Packaged goods
Packaged goods are products that are all of these:
- sold sealed
- between 5g and 25kg or 5ml and 25 litres
- the same weight or volume as other products of the same type
There are 2 ways to pack your products.
Minimum system
You can pack your products so that they contain at least the quantity displayed on the label. The packages can contain more than the label says, but not less.
Average system
You can pack your products to an average measurement that is on the label. You must check your packages to make sure a random sample is packed to meet all these rules - known as the ‘three packers’ rules’:
- the contents of the packages must not be less, on average, than the weight on the label
- only a small number can fall below a certain margin of error, known as the ‘tolerable negative error’ (TNE)
- no package can be underweight by more than twice the TNE
| Quantity in grams and millilitres | TNE as % of quantity | TNE in grams or millilitres |
|---|---|---|
| 5 to 50 | 9 | n/a |
| 50 to 100 | n/a | 4.5 |
| 100 to 200 | 4.5 | n/a |
| 200 to 300 | n/a | 9 |
| 300 to 500 | 3 | n/a |
| 500 to 1,000 | n/a | 15 |
| 1,000 to 10,000 | 1.5 | n/a |
| 10,000 to 15,000 | n/a | 150 |
| more than 15,000 | 1 | n/a |
If you’re calculating the TNE as a percentage of the quantity, you must round up the weight or volume to the nearest 0.10 of a gram or millilitre.
Contact your local Trading Standards office for help with packing to the average system.
Read the ‘Weights and Measures (Packaged Goods) 2006’ guidance for business for more information.
You must make sure packaged goods you’re producing or importing are packed and labelled correctly.
You can be fined or sent to prison if you break the rules.