A hemline is the bottom edge of a skirt, dress, or coat where the fabric has been folded and sewn to prevent fraying. The term also refers to how high or low that edge falls: a dress might have a hemline at the knee, above the ankle, or anywhere in between.

Fashion designers and clothing manufacturers pay close attention to hemlines because they dramatically change how a garment looks. A skirt with a hemline just below the knee creates a different impression than one with a hemline at mid-calf. Throughout history, hemlines have risen and fallen with changing fashion trends. In the 1920s, hemlines rose daringly to the knee, shocking people accustomed to floor-length skirts. By the 1960s, the miniskirt pushed hemlines even higher.

When you hem a piece of clothing, you're creating or adjusting that bottom edge, usually by folding the fabric over and stitching it in place. If you grow taller and your pants become too short, someone might need to let down the hem to lower the hemline. If a dress is too long, raising the hemline makes it shorter and easier to walk in.