The first thing almost everyone does with a similarity report is look at the percentage and decide, instantly, whether they're in trouble. It's understandable — it's the biggest number on the page. It's also the number that tells you the least.
A similarity score just measures how much of your text matches something already indexed somewhere. It has no idea whether that match is a properly cited quote, a shared phrase from a textbook everyone in the class used, or a paragraph lifted without attribution. Those all move the percentage the same way.
What actually determines if a score is a problem
"I panicked at 34% until I actually opened the report and saw it was almost entirely my properly formatted bibliography."
Instructors who read these reports regularly aren't looking at the top-line number either. They're looking at what's underneath it.
How to actually read the report
Open the source breakdown, not just the score
Every similarity report lists which sources matched which parts of your text. Start there — the score is just a sum of everything below it.
Check whether each match is cited
A matched passage with a citation attached to it is doing exactly what it's supposed to. The same passage with no citation is the actual issue.
Look at match length, not match count
Ten scattered three-word matches to common phrases matter far less than one uninterrupted forty-word match to a single source.
Rule out your own bibliography and quotes
Properly formatted reference lists and block quotes are supposed to match — most instructors read reports with this already excluded.
Worth knowing: different instructors and platforms configure similarity checks differently — some exclude quotes and bibliographies from the score automatically, some don't. When in doubt, ask what threshold your instructor actually uses before assuming a number is a problem.
See your report broken down, not just scored
Source-by-source matches, not just a percentage — so you know exactly what to fix.
Try TurnPro AIFree similarity reports and plagiarism checking for students.