The investigation sought to replicate previous Yamax physical education steps/min findings by quantifying physical activity via pedometry albeit with the Walk4Life (W4L) pedometer. Specifically, the objective was to determine steps/min cut point intervals for the 33% and 50% physical activity (i.e., percent of lesson time engaged in physical activity [%PA]) physical education guidelines via the W4L pedometer.Field-based criterion-referenced validation.Data were collected from 75 lessons on 411 fifth- through twelfth-grade (M age =13.83±2.17 y) participants who had concurrently measured pedometer and behavioural observation data. The W4L and Yamax pedometer outcome measure was steps/min, and observation measure was %PA. Pearson r correlation and diagnostic (i.e., sensitivity, specificity, and receiver-operating characteristic [ROC] curve) tests were conducted.(a) Steps/min and %PA demonstrated a strong relationship (W4L, r=0.96, p=0.0001; Yamax, r=0.96, p=0.0001), (b) W4L pedometer steps/min accurately discriminated (ROC area under curve≥98%) between achievement or non-achievement of %PA guidelines, (c) the W4L steps/min cut point intervals for the 33%PA guideline (55.0–59.5) were significantly lower than those found for the Yamax pedometer (60.8–65.0), and (d) a borderline overlap was found between W4L (75.7–79.5) and Yamax (79.1–85.8) steps/min cut point intervals for the 50%PA guideline.W4L steps/min demonstrated a strong relationship with %PA, and outstanding accuracy for physical education physical activity guideline discrimination; however, steps/min values indicative of physical education physical activity guideline achievement is pedometer brand dependent, and should be considered for steps/min implementation and surveillance.