The paper ‘The third-body approach: a mechanical view of wear’ by Maurice Godet (Wear, 100 (1984), pp 437–452) was perhaps the first to articulate clearly the key role of the rate of debris expulsion from a fretting contact in controlling the overall rate of wear. Whilst subsequent research over the past four decades has acknowledged this, the issue is generally addressed qualitatively rather than quantitatively. There are many parameters which will affect the rate of debris expulsion from a fretting contact, and amongst them is the physical size of the fretting contact. In this paper, for the first time, a physically-based relationship is proposed between the debris-expulsion-limited wear rate and the contact size. This relationship is able to account for differences in wear rates observed in tests conducted with different (and evolving) contact geometries (non-conforming contacts) over a range of durations, thus clearly demonstrating the validity of the approach. •Wear volume in cylinder-on-flat contacts is geometrically consistent.•W-shaped wear scars transform to U-shaped scars as the number of cycles is increased.•Debris egress from the contact normally controls the wear rate of the system.•Instantaneous wear rate is to proportional to the inverse of the scar width.•The contact-geometry dependence of wear rate is fully reconciled via this methodology.