The amount of plagiarism a document is allowed can vary. Different universities, courses and assignment types have different rules, and you can usually find out more about your institution’s accepted practices in your course handbook, or by asking your tutor. Typically, there is no hard or defined limit on a percentage of matching content. Each piece of work is unique, and often matches do not equal plagiarism: while some documents may have a high match percentage which looks worrying outright, they don’t necessarily feature much, if any, plagiarism.
Read more about the types of plagiarism and how to avoid it at in our help articles.
If you do have plagiarism in your paper, it’s best to look at what is plagiarised and where it is coming from. Make sure that you have referenced quotes and ideas properly, read more here about how to avoid plagiarism.