What Turnitin Percentage Is Acceptable? Good vs Bad Similarity Scores
There is no official Turnitin pass mark. Turnitin reports matching text; your instructor decides whether it is a problem. Still, markers use fairly consistent rules of thumb, and the percentage is only half of what they look at.
What Turnitin percentage is acceptable?
For most referenced coursework, a similarity score under about 15% is treated as acceptable, 15 to 25% is usually fine after a quick look, and above 25% needs explaining. For a dissertation, many supervisors use 10 to 20% with the bibliography excluded. If your course handbook names a figure, that figure overrides any rule of thumb.
| Work | Commonly accepted similarity |
|---|---|
| Essays and coursework | Under 15 to 20% |
| Literature reviews | Can run higher, up to about 25%, if well cited |
| Dissertations and theses | Often 10 to 20%, bibliography excluded |
| Journal submissions | Set by each journal; many query single-source matches above a few percent |
See also acceptable Turnitin score for a dissertation and what each percentage means.
Good vs bad Turnitin similarity percentage
| Percentage | How most markers read it |
|---|---|
| 0% | Fine, but unusual for a referenced paper; often means the bibliography and quotes were excluded |
| 1 to 15% | Good. Normal for referenced coursework if no single source dominates |
| 15 to 25% | Acceptable, worth a look; often quotes, common phrases or standard terminology |
| 25 to 50% | Bad for most assignments; expect questions about uncited matches |
| 50% and above | Very bad; usually investigated |
These are common practice, not Turnitin rules. Some departments set their own limits, and literature reviews or legal writing can run higher legitimately.
Why the percentage alone does not decide
Two reports with the same score can mean very different things:
| Paper A: 18% | Paper B: 18% | |
|---|---|---|
| Sources | 30 sources, each under 1% | One website at 16% |
| Match groups | Mostly Cited and Quoted | Mostly Not Cited or Quoted |
| Verdict | Normal referencing | Looks like copying |
What markers look at after the percentage
- Largest single source. Anything above roughly 5% from one source stands out.
- Not Cited or Quoted group. Uncited matches are the real concern.
- Submitted works. Matches to other students' papers get the closest scrutiny.
- Filters. Whether the bibliography and quotes were excluded.
- The AI report. A clean similarity score with a high AI score raises different questions.
A good similarity score next to a high AI score
The similarity sample scored 1%, a very good result, with two internet sources each under 1%. The AI sample for the same paper scored 51%. A good similarity percentage tells you nothing about AI.
Screenshots shown for illustration. Your own reports arrive as full PDFs in your dashboard.
Score too high? Read how to fix plagiarism flagged by Turnitin. To check your percentage before submitting, see how to test Turnitin.
Frequently asked questions
What is a good Turnitin similarity percentage?
For most referenced coursework, under about 15% with no single dominant source is considered normal. Your institution may set its own threshold.
What is a bad Turnitin similarity percentage?
Scores above about 25% usually get a closer look, and above 50% are often investigated. A low score with one large uncited match can also be a problem.
Is 0% similarity good?
It is fine, but unusual for a referenced paper. It can also mean the bibliography and quotes were excluded.
What Turnitin percentage is acceptable?
For most coursework, under about 15% is acceptable and 15 to 25% is usually fine after a look. Above 25% needs explaining. Your course handbook figure overrides these rules of thumb.