The basic idea is straightforward: to determine how much you should charge for a certain translation job, multiply your rate per word by the total number of words in the source text. This will give you the total amount that you should be paid for the job. Consider this scenario: you have been given a document of 2,000 words to translate. Assume further that you charge ten cents for each word of the original material.
A professional translation service is defined as the following:
A company or an individual may engage in a transaction known as professional translation services when they make a purchase of language translation from a company or an individual whose primary source of income is derived from the act of translating words.
I am using Google Translate))