How much AI percentage is allowed in a thesis?

There is no single limit. Each college or department sets its own rule, and Turnitin itself says its AI score should not be the only basis for any action. Ask your supervisor or exam office what your college uses before you worry about a number.

Written by Adithyan, a student who builds PaperCheck. Last updated 2 November 2026.

What Turnitin shows

Turnitin shows a real number only from 20% upward. Scores from 1% to 19% are hidden behind *%, because Turnitin treats them as less reliable. See what *% means and is 20% bad?

Who decides the limit

Your college or university sets any AI policy. Some have a number, many only look closer at high scores, and some have no rule yet.
Your supervisor usually reads the flagged parts, not just the total.
Similarity (plagiarism) limits are a separate rule. See UGC plagiarism rules for a thesis.

What to do before you submit

Ask in writing what AI score your college accepts, if any.
Check your thesis on the home page (5 free checks a week, up to 20,000 words).
Rewrite the flagged paragraphs with details from your own work: what you built, measured, and what went wrong.
Keep your drafts and notes. They are your best evidence if a score is questioned.

What nobody can promise

No tool, ours included, can tell you the exact score Turnitin will show, because you cannot see it in advance. A score from any detector is an estimate, not proof.

Common questions

Is there a standard AI percentage for a thesis?

No. It depends on your college or department.

Is 20% AI too much?

Not by itself. It is the lowest score Turnitin shows as a number, and what happens next depends on your college policy.

Can I check my thesis before submitting?

Yes. PaperCheck gives 5 free checks a week, up to 20,000 words each.

Check your paper: 5 free checks

More guides

PaperCheck is not affiliated with Turnitin, GPTZero, papercheck.in or papercheck.ai. Scores from any detector are estimates, not proof.