Flat

Flat covers everything from 0" to 1" of lift: ballet flats, loafers, most sneakers, flat sandals and flat boots. Within the band the heel and forefoot sit at effectively the same level. Your weight spreads naturally and your stride stays full length. The calf and Achilles work at their normal resting length. Nothing else in footwear walks further for less effort, which is why this band owns travel and errands.

Flat does not mean comfortable by default. A dead-flat, unstructured sole gives the arch nothing to rest on, and the thin ballet flat is the classic case. Over a long day the plantar fascia, the band of tissue running along the sole of your foot, takes the strain. Higher arches feel it most. A small rise of 0.5" to 1" plus a contoured footbed usually beats zero. The slight lift eases the Achilles, and the contour shares load across the arch.

Against the low band, flat trades polish for endurance. A 1.5" heel visibly lengthens the leg and dresses an outfit in a way no flat can, but a flat wins every contest measured in miles. Judge a flat by its footbed and sole thickness rather than its height. With no heel to discuss, cushioning and structure are the entire comfort story. A 0.2" difference in sole depth matters more here than anywhere else in footwear.