Each piece of writing is different and requires a different amount of work, so rates vary between $.015 and $.020 per word or £.012 and £.016 per word. (50,000 words = $750/$1000 USD or £600/ £800 GBP)
I usually edit between five hundred to eight hundred words, but if the writing is clean I often go farther—with the aim of helping you, the author, to see the quality, style, and tone of my work, and to decide whether you’d like me to be part of your team. For my purposes, the more manuscript I am given, the easier it is to assess a writer’s experience level and then to create a fair quote. However, while I’d be thrilled to see an entire manuscript, I’m happy to be given just a chapter or two.