The security mechanisms used to protect Internet-of-things and embedded systems often depend on cryptographic tools designed specifically to operate in resource-constrained environments. Several lightweight cryptographic ciphers have been proposed for such purposes, providing various properties and tradeoffs that balance security and performance. This paper provides a comprehensive evaluation of key lightweight ciphers, evaluating their throughput, processing efficiency, memory footprint, ROM utilization, and energy consumption. We focus on the software implementation and performance of these ciphers on a representative single-core ARM processor and propose an \({{\,\mathrm{\textit{E-Rank}}\,}}\) metric that combines essential performance characteristics with resource consumption into a single comparative metric. The metric aids in identifying lightweight ciphers that achieve an optimal balance of efficiency by normalizing the trade-offs between performance, memory usage, and energy consumption.