<p>Digital logic systems widely employ the full adder (FA) cell as a fundamental building block for binary arithmetic operations. Continuous research is being conducted to optimize FA designs with the goal of improving power efficiency, speed, and area utilization. Since the early development of CMOS logic circuits, numerous FA architectures have been proposed using a variety of logic styles and design strategies. In this study, 30 different full adder circuits are analyzed under standardized conditions to evaluate their performance. The analysis focuses on key parameters such as circuit type, method of carry generation, power consumption, propagation delay, and output voltage swing. The study reveals that the performance of FA circuits varies significantly depending on their internal logic and structural approach. Not all FA circuits provide practical effectiveness; for instance, some designs achieve low power consumption but suffer from degraded output voltage swing or generate carry outputs based on delayed sum outputs, increasing overall latency. Additionally, several designs incorporate approximate computing techniques, which simplify circuit complexity and reduce power usage at the cost of accuracy. These approximate FAs are well-suited for error-tolerant applications such as image processing, neural networks, and multimedia systems, where small inaccuracies do not critically affect overall performance. Overall, this comparative evaluation highlights that no single FA design is universally optimal. Instead, selecting the appropriate FA architecture should be guided by the specific performance and accuracy requirements of the intended application. The study serves as a valuable reference for designers aiming to balance power, delay, and output quality in modern digital circuit design.</p>