The purpose was to examine the agreement (convergent validity) between six measures of habitual physical activity to estimate durations of light, moderate, vigorous and total activity in a range of free-living individuals. Over seven consecutive days 49 Chinese (30 males, 19 females) aged 15-55 yr wore a Polar heart rate monitor (HRM), a uniaxial MTI and triaxial Tritrac accelerometer, plus a Yamax pedometer for 600 min^.d^-1. They also completed a daily physical activity log and on day-8 a Chinese version of the 7-d International Physical Activity Questionnaire. At each level of activity there was good agreement between the two questionnaire-derived instruments and the two accelerometry-derived instruments, but wide variation across different instruments, with 2-4 fold differences in mean durations often seen. The HRM overestimated light activity and underestimated moderate activity when compared to all other measures. Spearman correlation coefficients were low-to-moderate (0.2-0.5) across most measures of activity, with the pedometer showing correlations with total activity which were often superior to the other movement sensors. We conclude that using commonly accepted cut-points for defining light, moderate, vigorous and total activity, little convergent validity across the instruments was evident, suggesting these measures are sampling different levels of habitual physical activity and care is needed when comparing their results. To provide a more stable comparison of activity among different people, across studies, or against accepted physical activity promotion guidelines, further work is needed to fine-tune the different cut-points across a range of common activity monitors to provide more consistent results during free-living conditions.