The expansion rate of a translation is the percentage of additional characters and therfore additional space needed after translation. When you translate from English to French or Spanish, for example, you may look at around 20% text expansion. German may use the same amount of words or even less than English, but you still look at an expansion rate of up to 35%. The reason is that German has generally longer words plus the (in)famous compound words like Kraftfahrzeug-Haftpflichtversicherung (car insurance) or Nahrungsmittelunverträglichkeit (food intolerance).
When you take individual words for buttons or menu items, the difference can be even more striking. The menu item FAQ for example will be Preguntas frecuentes in Spanish, an increase of 700%! The opposite is the case for Arabic, Scandinavian and Asian languages. While Arabic translations will be around 15 % shorter than the English original, Chinese translations may be even up to 40 % shorter. The individual Chinese, Japanese or Korean characters, however, take up more space than the letters of the Latin alphabet. To come back to our FAQ example, this will also take more space in Korean(자주 묻는 질문) or Simplified Chinese (常见问题解答)
Unfortunately, there is no set percentage for each language pair as the expansion rate varies significantly depending on various factors, the most important one being subject matter. Legal or technical text translations, for example, will expand less than translations of literary texts.
Take Expansion Rates into account before Translation
- Allow for at least 30% more text when creating the original content. Menu items or buttons require even more flexibility.
- Create the content with translation in mind. This includes short, clear sentences. Use active voice rather than passive voice. Avoid abbreviations as they may not translate as abbreviations in the target language.
- The translators have to be clearly instructed about any specific character limits. Ideally, they can see the text in context while translating and adapt the translation to the available space. Many professional Translation Tools provide translation previews even for InDesign files nowadays.
- For website translations, consider translating through a Translation Proxy which allows for translation in-context
Character Limits in Google Ads and Search Engine Results Pages
Another area where text expansion can cause issues are Google Ads or PPC. In these cases, we’re entering the area of transcreation as a direct translation won’t work anymore. Instead, the translator will need to rewrite the ads in a creative way to get the same message across and not exceed any character limits.