Oval - Length equals around one and a half times width
As oval is considered to be the ideal face shape it is therefore the most versatile, so nearly every hair style will look good on this face. You can wear short, medium or long hair styles. Your face shape is in even proportion.

Round -  Round hairline and chin line, wide face and round cheeks
If you have a round face shape, the goal here is to slim the face. Hair below the chin line should be worn with a face-lengthening center parting. For hair above the chin line, wear an off-center parting to break up the roundness. 

Square - straight hairline, angular jaw with wide face
Your hairstyle should try to soften the sharp angle of your jaw line and minimize a squared-off forhead look. Hairstyles that emphasize the cheekbones are most flattering, so short layers (cut into longer hair) that swing foreward onto cheekbones will look great. 

Oblong - Long and slender, about the same width at forehead and just below cheekbones. May have a very narrow chin or a very high forehead.
Hairstyles for this face shape should add width and fullness to the sides of the face and around the eyes, cheekbones and ears. This shape benefits from a low side parting, with a sweep of hair brushed across the forehead and secured with a  butterfly clip.