Background:Accurate estimation of fetal gestational age (GA) is critical for optimal prenatal care. Fetal foot length (FFL) has emerged as a promising alternative due to its relatively stable growth pattern throughout gestation. Additionally, the femur-to-foot length (FL/FFL) ratio has been proposed as a method to enhance GA estimation accuracy. Aim:This study aimed to assess relationship between sonographic GA and FFL. Materials and Methods:A prospective observational study was conducted in the Department of Radiology at Aarupadai Veedu Medical College and Hospital, Puducherry. A total of 90 antenatal women with singleton pregnancies between 16 and 34 weeks of gestation were included. FFL and femur length were measured using a Mindray DC 80 ultrasound scanner. Pearson correlation analysis and independent t-tests were performed using SPSS version 26.0, (IBM Corp., Armonk, NY) with significance set at P < .05. Results:GA corresponded with ultrasound findings in 93.3% of participants. A strong positive correlation was observed between GA and FFL (r = 0.899, P < .001). Additionally, FFL correlated significantly with BPD (r = 0.915), HC (r = 0.918), AC (r = 0.914), and FL (r = 0.955) (P < .001 for all). The FL/FFL ratio remained stable mean value of 1.0132, reinforcing its reliability as a supplementary marker. Conclusion:Fetal foot length is a reliable marker for GA estimation and exhibits strong correlations with other biometric indices. The stable FL/FFL ratio further supports its use as a supplementary parameter in assessing fetal growth.