The current British mess - of being half metric, half imperial - causes a number of serious problems:
- Consumers have difficulty in comparing prices (and hence value for money) when rival traders quote prices in different measures - for example, if one trader's prices are in £/kg and the neighbouring trader quotes in £/lb. Dual pricing (e.g. per kg and per lb) increases costs for manufacturers and causes unnecessary work for retailers – especially small shopkeepers and market traders who may have to change prices frequently by hand. These costs are ultimately borne by the consumer. Similarly, the marking of package sizes in both metric and imperial has a cost implication.
- Misunderstandings, mistakes and disputes can occur when parties to a transaction use different units of measurement. (The 1999 failure of the Mars Climate Orbiter space probe at a cost of $125 million is the best known and most spectacular example.)
- Much teaching of metric to schoolchildren is wasted, since they have little opportunity to practise their skills outside school. When children leave school, they have to adapt to the imperial system, which they have not been formally taught. Many soon forget what they learnt at school yet have an imperfect grasp of and no ability to calculate in imperial measures. This could have serious consequences for road safety.
- The emphasis on conversions (from metric to imperial and vice versa) inhibits people from thinking easily and consistently in a single system. People who use metric at work constantly have to adjust to the imperial environment outside the workplace.
- Standard derived measures, such as fuel consumption in miles per gallon or in litres per 100 kilometres, cannot easily be calculated when a mixture of units (litres and miles) is used.
- Road contractors have to convert metric design distances into imperial for signage with consequent costs and potential for error.
- People purchasing properties have to do extensive conversions from metric to imperial and vice versa if they wish to estimate costs of renovations.
- Power output of different appliances cannot be compared when some (e.g. central heating boilers) are expressed in "British thermal units" (BTUs) and others (such as electric heaters) are expressed in kilowatts.
- Overseas visitors are confused by the inconsistent mixture of measures used.
UKMA believes that this confused muddle of two incompatible systems is an unacceptable situation which cannot be allowed to continue indefinitely. Unfortunately, the UK government (like its predecessors) appears unwilling to admit or address the problem and has no current plans to do anything to resolve the situation.
UKMA believes that the only solution is to standardise on a single system - as soon as practicable.