Objective The current study aims to compare between mid-thigh soft tissue formula and modified mid-thigh soft tissue formula with Hadlock formula in estimation of fetal weight. Materials and methods Two hundred full term pregnant women attending Ain Shams Maternity Hospital in the period from April 2018 and April 2019 were included in this comparative study. Whole study group (200 women) had 2D ultrasonography using Hadlock's formula, thigh soft tissue formula and Modified thigh soft tissue formula. Results In our current study Hadlock's formula was better than thigh soft tissue and modified thigh soft tissue formula in estimation of fetal weight. Conclusions Fetal mid-thigh SST is a simple, useful, and easily applicable parameter for fetal weight estimation.