Abstract—This paper describes T-SIZE, a peer counting protocol that is based on gossip-based aggregation. Peer counting has become increasingly important as the size of the network is often a crucial parameter used to guarantee robustness, small diameter, load-balance, or to generally optimize the system. Our work improves the previous work by providing a protocol that is eventually accurate, i.e. the estimate will eventually converge to the true peer count in absence of churn. The protocol can handle extreme levels of churn, and automatically ensures that all participating nodes learn the outcome of the peer counting.