An important task for network operators is to properly dimension the capacity of their links. Often, this is done by simple rules of thumb based on coarse traffic measurements provided, e.g., by SNMP. More accurate estimations of the required link capacity typically require packet-level measurements, which are hard to implement in today’s high-speed networks. The challenge is, therefore, to accurately estimate the traffic statistics needed for estimating the required link capacity with minimal traffic measurement effort. This paper proposes a novel, hybrid procedure for link dimensioning that combines flow-level measurements, minimal efforts on packet captures, and an analytical traffic model. The result is an efficient and robust method to estimate required link capacities. Although the idea of estimating required capacities from flows is not new, the novelty of this paper is that it proposes a complete, efficient and deployable procedure. The proposed procedure has been extensively validated using real-world traffic captures dating from 2011 to 2012. Results show that, with minimal measurement effort, we are able to efficiently estimate the required bandwidth at timescales as low as 1 ms.