In the guide
In this guide, the words 'must' or 'must not' are used where there is a legal requirement to do (or not do) something. The word 'should' is used where there is established legal guidance or best practice that is likely to help you avoid breaking the law.
This guidance is for England, Scotland and Wales
Metric units
If you are indicating units of weight or volume, only the permitted abbreviations (symbols) can be used. These are shown in the table below.
| Unit of measurement | Symbol |
|---|---|
| Metre | m |
| Centimetre | cm |
| Millimetre | mm |
| Square metre | m2 |
| Cubic metre | m3 |
| Litre | l or L |
| Centilitre | cl or cL |
| Millilitre | ml or mL |
| Tonne | t |
| Kilogram | kg |
| Gram | g |
| Milligram | mg |
Vulgar fractions are not permitted (unless it relates to a fraction of a pint). For example, 500 g cannot be expressed as 1/2 kg.
If the word 'net' is used, it cannot be abbreviated.
Back to topSupplementary imperial units
Imperial units can be shown as well, but they must not be more prominent than the metric indication. The permitted units are shown in the table below.
| Unit of measurement | Abbreviation |
|---|---|
| Yard | yd |
| Foot | ft |
| Inch | in |
| Square yard | sq yd |
| Gallon | gal |
| Quart | qt |
| Pint | pt |
| Fluid ounce | fl oz |
| Pound | lb |
| Ounce | oz |
Except where the law and trade practice dictates otherwise, liquids should be marked with a volume (ml or L, for example) and other products by weight (g, kg, etc).
Under the Weights and Measures (Quantity Marking and Abbreviations of Units) Regulations 1987, quantity indications must be easily visible, legible and indelible. Under the Weights and Measures (Packaged Goods) Regulations 2006, they must also be of a minimum height, depending on the pack size.
Back to topTrading Standards
For more information on the work of Trading Standards services - and the possible consequences of not abiding by the law - please see 'Trading Standards: powers, enforcement and penalties'.
Back to topIn this update
No major changes.
Last reviewed / updated: October 2024
Back to topKey legislation
Please note
This information is intended for guidance; only the courts can give an authoritative interpretation of the law.
The guide's 'Key legislation' links may only show the original version of the legislation, although some amending legislation is linked to separately where it is directly related to the content of a guide. Information on changes to legislation can be found by following the above links and clicking on the 'More Resources' tab.