What Duolingo score do you need for Stephen F. Austin State University?

The English proficiency page lists Duolingo as accepted for undergraduate admission only, and the graduate admissions page names TOEFL and IELTS as the official exams for graduate applicants. All English tests must have been taken within the last two years to be valid.

The page gives no Duolingo subscore rule.

For comparison, the same page sets IELTS at an overall band of 6.5.

SFA accepts completion of Level 112 at an ELS Center, or Level 160 or 150 with set grades at the Texas Intensive English Program, in place of a test. Recent US school or college credentials and some transfer records also meet the requirement, and waivers apply for some countries.

Requirements vary by programme and change between admissions cycles. The score that binds you is the one on your SFA programme page and in your offer letter, so check it there before you book a test.