PURPOSES : In this study, the flatness of a sidewalk surface was evaluated by measuring the vibration acceleration experienced by wheelchair users passing the sidewalk using a walking measure. The objective of this study is to derive a linear equation for converting the vibration acceleration of a sidewalk surface measured using a walking measure into vibration acceleration of a wheelchair. METHODS : To this end, field measurements were obtained. Twenty sites with different sidewalk surface materials were selected to measure the vibration accelerations of the walking measure and wheelchair. A regression analysis was conducted with the measured root mean square value of the vibration acceleration, and a linear equation expressing the walking measure and wheelchair vibration acceleration was derived. RESULTS : The regression analysis was conducted by inputting the vibration acceleration of the wheelchair into the Y-axis and that of the walking measure into the X-axis. Thus, a linear equation between the walking measure and wheelchair acceleration could be derived. Further, linear equations could be derived and applied based on the situation using various standard walking measures and wheelchairs. These equations could be used to convert the vibration acceleration of the walking measure into that of the wheelchair. Substituting the converted vibration acceleration into the comfort level specified in ISO 2631-1 was expected to indicate the flatness of the sidewalk. CONCLUSIONS : This study confirmed that a linear equation for the two vibration accelerations could be derived by measuring the vibration accelerations of the walking measure and wheelchairs of 20 different sites. The vibration acceleration measured using the walking measure could be converted into that of the wheelchair using this linear equation. In addition, the flatness of the sidewalk could be evaluated by measuring the vibration acceleration of the walking measure using this linear equation.