The strength of influence of the aspects depends on the planets involved and how they relate to each other. The closer the aspect occurs within its orb the more important it becomes, whether it be a major or a minor one. In natal charts, the accepted orbs are 9 to 10 degrees for oppositions and conjunctions, 7 to 9 degrees for trines and squares, 4 to 6 degrees for sextiles, 2 degrees for quincunxes and sesqui-squares, around 1 degree for semi-sextiles and semi-squares.
The Major aspects used in astrological calculations are the conjunction (0°), the opposition (180°), the square (90°), the trine (120°), and the sextile (60°). Minor aspects used include the inconjunct (150), the semi-sextile (30°), the quintile (72°), the semi-square (45°), and the sesquiquadrate (135°).