It is true that a work of writing usually benefits from being trimmed: it strengthens and concentrates the message. However, the ‘cut 10%’ rule of thumb is just plain silly if, like me, you under-write rather than over-write (I generally have to add, add, add before I can even think about cutting). And the idea that once you hit the magic 10% of your word count, you’re suddenly finished trimming is also unrealistic.
This rule is better described as: every word should be doing a job. This is related to the other rules and means that if you’ve used three words to describe one thing, maybe you should be working harder on picking the right verb or noun instead. Maybe you should be avoiding qualifiers like ‘quite’ and ‘kind of’. Maybe you should be avoiding repetition or thinking about whether the reader really does need that detailed description of the door knob.
Every sentence should be doing a job. Does that sentence or paragraph, that flashback or daydream or musing add to the characterisation, the world, the plot, or is it just that you developed this background for the character and you want the readers to know about it, damnit.
And do you need to tell the reader something six times, or will three times do? Will maybe just the once do, and you can trust your reader to know that if you mentioned it, it’s important? Can you perhaps even trust your reader to get the idea if you don’t come right and say it, because of how well you’ve drawn your characters and their emotions and relations?
Sometimes in the effort to get a description across, you might describe the same reaction or feeling two or three times using different imagery. But one well-chosen consistent image will be so much stronger than stringing together a series.
In the trimming process, don’t aim to cut 10% of your word count. Aim to cut every unnecessary word, whether that amounts to 5%, 20%, 50%…

Couldn’t agree more. And anyone who says “cut 10%” is a bloody idiot. You cut as much as needs to be cut to make the writing as good as it can be. There’s no formula to that.
Hi Trudi, thanks for dropping by.
I think the problem of thse over-applied rules arises because beginner writers in particular do reach for ‘formulas’ in search of some kind of guarantee that their writing will be ‘good’ instead of trusting themselves.
True. It is very hard to trust yourself as a writer – even when you’ve moved beyond the beginner bit, sometimes. That’s why reading these sorts of posts helps to consolidate at any level. Another well timed reminder just when I’m starting to edit – goodonya Wendy!
Thanks Alyson, glad it’s helped you, good luck with the editing…
[...] and adverbs II. Don’t consult your thesaurus Kill your darlings Write what you know Cut 10% in editing Avoid adjectives and adverbs Show, don’t tell Just keep writing Possibly related posts: [...]
I underwrite too, but i had to cut out 50% of first 6 chapter (and killed off the second chapter) from my story, because i have to change how it does start. after chapter 6 I noticed i cut less. When i wrote chapter 6, i knew better my character and where the story was going.
On the other hand, now i have to add parts that explain better what happens before chapter 6.
Hilariously, my final edits tend to be 10% longer.
Great post, Wendy. I don’t think Trudi’s comment that anyone who says “cut 10%” is an idiot is fair though. It’s a rule of thumb, not a hard and fast rule, and it’s often given after having read someone’s work. Stephen King mentions it in On Writing as formative advice he received early in his career. I got the impression he still uses the rule, because it works for him. If nothing else, having that goal can force you to make the hard cuts, and give you an exercise in demanding each word is working for you. If your work isn’t better (and be honest) after cutting something, you can always put it back in.
I tend to underwrite, as well. Nice to know I’m not alone. Thought I was a freak, since I’d always been told to expect editors to cut out entire chapters, not ask for more!