The average turnaround of a professional translator is usually considered to be around 2,500 words per day. Depending on the level of technicality and the format of the document to be translated, the turnaround can be up to 3,500 words a day or, on the contrary, the job can require more time.
All my translation orders include 2 self-proofreadings before delivery. If needed, for particularly complex jobs, I can also arrange for an independent reviewer to have one final look at your text.

For translation, rates are often given per source word and represent an average estimate of the amount of work and the expertise brought by the translator to the project. Thus they vary depending on the level of specialisation or technicality of the source text (that can require a lot of research on terminology and context), the source language and the format of the source text (a press release in a docx file will require almost no formatting work contrary to a scanned diploma in pdf).
For reviewing, the price can be counted per source word or per hour. We discuss together, at the quotation stage, what sort of rates are best suited, according to the nature of the work.
All my quotes clearly state the total price or estimate amount, to avoid any surprises, along with the breakdown of the applicable rates and the volume.

There are different types of reviewing.
After the translation work is done, it can be best to have the translation reviewed by another translator, to ensure that the original meaning is conveyed in full by the final document. It is not about re-translating the text, rather about bringing a fresh pair of eyes to the document. For this kind of reviewing, I check the source-text along with any reference material available to achieve optimal terminology accuracy and consistency of the translated text within its context.
For content destined to be published, for example a website or an academic thesis, your document may require a proofreading, to “polish” the writing style, spot the last typos, check the spelling and eliminate any residual awkward turn of phrase. My experience as a French teacher provided me with the necessary skills to carry out quickly but carefully this meticulous work.
Feel free to contact me to discuss which sort of reviewing is best suited to your needs.

To estimate the volume of your document, if it is a MS Word, LibreOffice or OpenOffice file, you will find the wordcount in the Statistics located in Properties in the File drop down menu.
For other formats or for hard copy documents, send me a copy or a scan and I will work out the volume for you.