<P> In 1965, the then Federation of British Industry informed the British Government that its members favoured adopting the metric system . The Board of Trade, on behalf of the Government, agreed to support a ten - year metrication programme . There would be minimal legislation, as the programme was to be voluntary and costs were to be borne where they fell . Under the guidance of the Metrication Board, the agricultural product markets achieved a voluntary switchover by 1976 . The stone was not included in the Directive 80 / 181 / EEC as a unit of measure that could be used within the EEC for "economic, public health, public safety or administrative purposes", though its use as a "supplementary unit" was permitted . The scope of the directive was extended to include all aspects of the EU internal market as from 1 January 2010 . </P> <P> With the adoption of metric units by the agricultural sector, the stone was, in practice, no longer used for trade; and, in the Weights and Measures Act 1985, passed in compliance with EU directive 80 / 181 / EEC, the stone was removed from the list of units permitted for trade in the United Kingdom . In 1983, in response to the same directive, similar legislation was passed in Ireland . The Act repealed earlier acts that defined the stone as a unit of measure for trade . (British law had previously been silent regarding other uses of the stone .) </P> <P> The stone remains widely used in the UK and Ireland for human body weight: in those countries people may commonly be said to weigh, e.g., "11 stone 4" (11 stones and 4 pounds), rather than "72 kilograms" as in many other countries, or "158 pounds" (the conventional way of expressing the same weight in the US). The correct plural form of stone in this context is stone (as in, "11 stone" or "12 stone 6 pounds"); in other contexts, the correct plural is stones (as in, "Please enter your weight in stones and pounds"). In Australia and New Zealand, metrication has almost entirely displaced stone and pounds since the 1970s . </P> <P> In many sports in both Britain and Ireland, such as professional boxing, wrestling and horse racing, the stone is used to express body weights . </P>

What do the british use to measure weight