A 3.5 GPA is below Yale's admitted middle-50% GPA range of 3.94–4.0.
On GPA alone this is a reach — to be competitive you'd want strong test scores, a demanding course load, and a standout application to offset it.
A GPA is the single biggest academic factor, but it's necessary, not sufficient — especially at a 3.9%-acceptance school like Yale. Your test scores, course rigor, extracurriculars, essays, and any standout achievements all move the number. The estimate above assumes typical scores and rigor; your real odds depend on your full profile.
Estimates are CDS-based and for a typical applicant. Run your full profile for your real, calibrated odds.