When it comes to order translation services, most people think of the words, not of the numbers. Nevertheless, when the numbers come together with units, the number-unit combination very often has to be localized. In case that the text you want to have translated contains units, you should first answer yourself the following:
Does my text contain units that are unusual in the country or countries the translation is intended for?
This very often is the case for translations from English to German, as in the United States, Canada, and the United Kingdom the use of non-metric or other local units is quite common, whereas in Germany the units are metric. Just think of the units “inch”, “foot”, “yard” oder “mile” used for designating a length or “pint”, “gallon”, etc. for volumes. Most Germans wouldn’t have a clear idea about what these units really represent. On top of that, these units vary from country to country. So, a gallon in the US is not the same as a gallon in the UK. In most of these cases, a conversion into metric units (metres, litres, kg, etc.) is recommendable. (Caution! Converting units may be a source of errors. Make sure, that the numbers are converted correctly, and let them be checked twice.) Sometimes, it also could make sense to maintain the original number and unit in brackets after the converted value. Finally, it’s up to you to choose the right solution for your text. To make the solution finding easier, you should ask yourself a second question:
Who is the target audience for the translation?
If the translation is made for experts in the matter, it’s quite probable that they know the original units, so you don’t have to change anything. If your text is intended for the average consumer, we are talking about a totally different issue, and you should opt for the common units in the respective country.
Whatever you decide, you should never forget the following: Let your translator know about your decision! He or she will be able to create a suitable translation only, when he or she knows your requirements. However, if your translation will be done by an experienced translator, he or she will contact you anyway, and ask you about your preferences in case of doubt.
If you are not sure about what to do, just ask your favourite translator. He or she will be happy to provide you with advice.