A new adaptive circuit design approach is proposed and analyzed employing independently biased back-gated Double-Gate MOSFET (DGMOSFET) devices. Threshold voltage tuning using back-gate of the DGMOSFET was compared with a conventional body-bias method. The technique is a promising solution to control the transistor's threshold voltage while reducing undesirable effects at the sub-50-nm device technology nodes. An automatic adaptive circuit for threshold voltage tuning was implemented using DGMOSFET devices in 45 nm CMOS technology. Simulation results show that this circuit compensates for static and dynamic variations. This adaptation approach using DGMOSFETs along with adaptive supply voltage scaling allows simultaneous optimization of power and performance according to application-specific workload and requirements. Simulation results using a 45 nm CMOS technology indicate that this adaptive circuit design can provide 50% higher performance for the same energy, or consume 40% less energy for the same performance. In contrast to conventional methods which only employ dynamic voltage scaling, adaptive tuning of threshold voltages reduces power consumption while maintaining its noise margin. © 2004-2012 IEEE.