Double-helical gear is combined with the left and right-handed helical gears with the same twist angle, which smoothly transmits power between two parallel shafts on heavy loads for reduced noise and vibration operation. The helix angles influence the stress and deformation of double-helical gears before structural failures or breakdowns. Thus, variations in helix angles can result in wear, fatigue, increased stress, misalignment, and uneven load distributions. In this study, we modelled double-helical gear using SolidWorks software. By applying ANSYS 23.0, the effcets of helix angles on the stress distribution and overall performance were investigated. The evaluated data from both the ANSYS and AGMA (American Gears Manufacturing Association) approaches were compared, and this comparison achieved the result of a decrease in stress and strain with an increase in helix angle along the wider face width. At a helix angle of 30° and a constant value of face width, the stresses were found to be 1.4491 MPa and 1.5346 MPa for pressure angles of 20° and 14.5°, respectively, in ANSYS. After the comparison, discrepancies of 0.287% and 6.204% were identified between the evaluated stresses from the ANSYS and AGMA standards.