Activated　carbon　is　widely　used　as　electrode　materials　in　supercapacitors,　and　its　capacitive　performance　is　significantly　influenced　by　the　specific　surface　area.　However,　different　types　of　wall　surfaces,　such　as　basal-,　edge-　and　defect-surfaces,　exist　in　carbonaceous　materials　due　to　the　complex　structure　and　atomic　distribution　of　carbon　atoms,　rendering　different　influences　on　capacitive　charge　storage　behavior.　Therefore,　it　is　of　utmost　significance　to　quantitatively　determine　their　contribution　to　the　capacitive　performance.　Herein,　the　commercial　graphite　powder　is　ball　milled　to　introduce　different　types　of　edges　and　defects,　resulting　in　different　proportions　of　basal-,　edge-　and　defect-surfaces.　Moreover,　a　modified　non-local　density　functional　theory　calculations　method　is　adopted　to　quantitatively　evaluate　the　basal-,　edge-　and　defect-surface　area.　Then,　a　relationship　is　established　between　the　electrode　capacitance　and　wall　surface　area　by　the　linear　regression　method.　The　results　reveal　that　the　basal-,　edge-　and　defect-surfaces　contributed　an　areal　capacitance　of　0.04　μF　cm−2,　1.65　μF　cm−2　and　7.95　μF　cm−2,　respectively.　Hence,　the　capacitance　is　mainly　provided　by　the　defects　of　wall　surfaces.　©　2020　Elsevier　B.V.