In this paper, we first establish that, in wireless sensor networks, operating over ldquosmallrdquo distances, both computation energy and radio energy influence the battery life. In such a scenario, to evaluate the utility of error-correcting codes (ECCs) from an energy perspective, one has to consider the energy consumed in encoding-decoding and transmitting additional ldquoredundantrdquo bits vis-a-vis the energy saved due to coding gain. This paper presents a framework for evaluating various ECCs based on a comprehensive energy model of a sensor node. The framework supports exploration of sensor node design space with application- and deployment-related parameters, like distance, bit error rate, path loss exponent, as well as the modulation scheme and ECC parameters. The exploration results show that, as compared to the uncoded-data transmission, the energy-optimal ECC saves 15%-60% node energy for the given parameters.