The explosive growth of the Internet has induced a need for developing tools to understand the composition and dynamics of the Internet traffic. Measurements of the various characteristics of a network provide insight into the state and performance of the network whether it is behaving as expected and whether changes in the network have improved or degraded its performance. Available bandwidth on the links of a network is an important metric which can predict the performance of the network. In this paper, an estimation algorithm for the available bandwidth on a link is presented. The algorithm estimates the available bandwidth and tells the duration for which the estimate is valid with a high degree of confidence. The algorithm dynamically changes the number of past samples that an used for prediction and also the duration for which the prediction holds.