A simple method for evaluating force (F), velocity (V) and power (P) output during a squat jump (SJ) was validated by Samozino et al. (2008, J Biomech, 41: 2940–5), who also showed the existence of an optimal force-velocity profile during SJ (2012, MSSE, 44(2):313–22). Counter Movement Jump (CMJ) is a very common test in sports training and testing (Markström and Olsson 2013, JSCR, 27:944–53). The aims of this study was to test the validity of this simple calculation method to evaluate muscle mechanical characteristics of lower limb extension (F, V and P) during a CMJ from three simple parameters: body mass, CMJ height and height of push off (Hpo). Sixteen high-level sprinters performed maximal CMJ against five additional loads (from 17 to 87 kg). Vertical ground reaction force was recorded and synchronised with vertical displacement (1000 Hz). For each condition and from both force plate measurements and the proposed simple computation method (Samozino et al. 2008), mean F, V, and P were determined over the entire push-off phase, and used to determine individual linear F-V relationships and associated maximal force (F0), velocity (V0) and power (Pmax) values. The absolute bias was calculated for each parameter: Bias = (Simple Method-Reference Method)/Reference Method ·100. Mean absolute bias were 1.47% (±0.01), 4.73% (±0.04), 3.19% (±0.03), and 5.84% (±0.04) for F0, V0 and Pmax, respectively. Correlations between the two methods were significant for all parameters (r from 0.97 to 0.99, p < 0.001). These results, and Bland and Altman analyses, support the validity of this simple method in CMJ. Consequently, the proposed method, based on three simple parameters only (body mass, jump height and Hpo), allows to accurately evaluate lower limbs force, velocity and power properties during loaded CMJ in field conditions. Coaches could use this method to quantify individual athlete Pmax and FV profile, and individualise their training regimens accordingly.