Background: This study aimed to investigate whether the diameter of antral follicles, specifically comparing those with diameters of 6 mm or less (AFC≤6) versus those greater than 6 mm (AFC > 6), can predict ovarian responsiveness, as assessed by the Follicular Output Rate (FORT) in women undergoing IVF treatment.138 women with regular menstrual cycles and no ovarian abnormalities, undergoing controlled ovarian hyperstimulation (COH) were included in this study. Number and size of antral follicles were noted on day 2 of cycle. Number of pre ovulatory follicles were noted and FORT was calculated on day of trigger with HCG. The correlation among FORT with age, AFC ≤ 6, AFC > 6, number of oocytes, body mass index (BMI), and antiMullerian hormone (AMH) were also assessed. Result: The mean age of the women was 31.36 (± 3.28) years, the mean FORT was 53.453. We found positive correlation between the FORT and antral follicles with diameter ≤6mm (r= 0.467, P 6mm in diameter (r = − 0.436, P<0.001). Conclusion: Ovarian responsiveness, as indicated by the Follicular Output Rate (FORT), was positively correlated with the presence of smaller antral follicles (AFC ≤6mm).