US Patent 10937457 Magnetic recording medium

There is provided a magnetic recording medium of which an average thickness tT is tT≤5.6 μm, a dimensional change amount Δw in a width direction with respect to a change in tension in a longitudinal direction is 660 ppm/N≤Δw, a squareness ratio in a vertical direction is 65% or more, and a width deformation coefficient b during long-term storage in a case where a long-term storage width change amount Y is defined as Y=blog(t) is −0.06 μm≤b≤0.06 μm.