The Scale with which the Internet of Things (IoT) is penetrating in our day to day life, time is not far away when it would be the Internet of Everything (IoE). That will require billions of devices to communicate with each other in the real world. To cater to the same, Wireless Sensor Network (WSN) is composed of 6LoWPAN sensor-nodes, which are mainly battery operated. One of the major issues, in such a network, is nodes’ limited lifetime which is battery dependent. In this paper, we have suggested and implemented an approach for ‘Estimation and Enhancement of Lifetime of Wireless Sensor Network’ (E&EL-WSN). The aim of our study is to suggest an approach that helps in power saving of the batteries of sensor-nodes and will result in an enhanced lifetime of 6LoWPAN environment. Our suggested approach is based on the concept of reduced packet size resulting in saving of power consumption. Packet size is reduced by our Modified and Improved Header Compression (MIHC) method of IPv6 header compression. The simulation, done in Cooja, shows, in our case, an improvement of approximately 19% saving of power consumption. This results in an enhancement of 70 days in the lifetime of the network, which is almost 23% better than existing approach.