Multi-path TCP (MPTCP) has been standardized by IETF and being used in practice. However, the MPTCP performance analysis has been paid less attention than algorithm improvement, such as coupled congestion control between subflows. The existing analytical models lack consideration of both slow start and congestion avoidance phases. In this letter, we perform a full analysis to derive the MPTCP performance by considering both the phases in the network with shared bottleneck so that we can calculate data transfer latency as well as throughput for a given size of data. Via direct code execution on top of the NS-3 simulation, we show that the proposed analysis captures data transfer latency under packet losses due to buffer overflow.