Units of measurement


The correct abbreviations (symbols) to use when indicating units of weight or volume for trading purposes

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.

Metric measurements
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 1/2kg.

If the word 'net' is used it cannot be abbreviated.

Supplementary 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.

Imperial measurements
Unit of measurement Abbreviation
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; they must also be of a minimum height, depending on the pack size.

Trading 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'.

Key legislation

Last reviewed / updated: June 2021

In this update

No major changes

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 amendments to legislation can be found on each link's 'More Resources' tab.

© 2021 itsa Ltd.

TSI: 329356, ID: 528, updated 15/06/2021