Romaji.me and Lingvozone.com have online translation applications that can translate English to Romaji. Romaji.me allows users to translate a single word up to multiple paragraphs to Romaji, Hiragana, and Katakana. Lingvozone.com only translates one word at a time but also features synonyms and definitions.
Another, slightly more complex way to translate English to Romaji is to use Google Translate to convert an English word or phrase into Kanji, labeled as Japanese, and then copy and paste the result into Romajidesu.com to translate it to Romaji. In addition to the Romaji phrase, Romanjidesu.com also translates the Kanji phrase back into English. This may help users to avoid translation errors, particularly when translating full sentences.