Supergranules are convection cells seen at the Sun ’ s surface as a space filling pattern of horizontal flows . While typical supergranules have diameters of about 35 Mm , they exhibit a broad spectrum of sizes from \sim 10 Mm to \sim 100 Mm . Here we show that supergranules of different sizes can be used to probe the rotation rate in the Sun ’ s outer convection zone . We find that the equatorial rotation rate as a function of depth as measured by global helioseismology matches the equatorial rotation as a function of wavelength for the supergranules . This suggests that supergranules are advected by flows at depths equal to their wavelengths and thus can be used to probe flows at those depths . The supergranule rotation profiles show that the surface shear layer , through which the rotation rate increases inward , extends to depths of \sim 50 Mm and to latitudes of at least 70 \arcdeg . Typical supergranules are well observed at high latitudes and have a range of sizes that extend to greater depths than those typically available for measuring subsurface flows with local helioseismology . These characteristics indicate that probing the solar convection zone dynamics with supergranules can complement the results of helioseismology .