The use of WMNs as backbone for large wireless access networks imposes strict bandwidth requirements. It is therefore necessary to study and quantify the capacity of such systems. In this paper, we argue that the capacity of WMNs should be addressed in the context of fairness to ensure proper operation of WMNs. Among the fairness schemes, max-min fairness allows fair and efficient use of network resources. We therefore propose an algorithm for max-min capacity calculation, formulated in term of collision domains. In addition, we show how to calculate the effective load of collision domains, assuming IEEE 802.11 as the MAC protocol. We illustrate our proposed algorithm and validate our results over baseline and general topologies