A pneumatic tire, comprising: a tread that contacts a road surface; and a plurality of grooves (14, 16, 20) that are provided at the tread and that partition a land portion, wherein, taking a groove side-wall to 1/2 the depth of the groove from a tread face of the tread as a first groove side-wall (16Fa, 16Ka), and taking a groove side-wall from 1/2 the groove depth to a deepest portion of a groove bottom as a second groove side-wall (16Fb, 16 Kb), A is less than B, wherein the plurality of grooves (14, 16, 20) includes a center circumferential direction groove that extends around the tire circumferential direction on a tire equatorial plane, a plurality of lug grooves that extend from the center circumferential direction groove toward contact edges, and a plurality of shoulder-side circumferential direction grooves that are formed on both tire width direction sides of the center circumferential direction groove so as to couple together one lug groove and another lug groove that are adjacent to each other in the tire circumferential direction, wherein A is an area, when viewed in a cross-section orthogonal to a length direction of the groove, of a region enclosed by a first imaginary line (FL3, FL7) passing through an end portion on a tread face side of the first groove side-wall (16Fa, 16Ka) and perpendicular to the tread face, by a second imaginary line passing through an end portion on a groove bottom side of the first groove side-wall and orthogonal to the first imaginary line (FL3, FL7), and by the first groove side-wall (16Fa, 16Ka), and B is an area, when viewed in a cross-section orthogonal to the length direction of the groove, of a region enclosed by a third imaginary line (FL4, FL8) passing through an end portion on the groove bottom side of the first groove side-wall (16Fa, 16Ka) and perpendicular to the tread face, by a fourth imaginary line passing through the deepest portion of the groove bottom and parallel to the tread face, and by the second groove side-wall (16Fb, 16Kb), wherein a ratio b/c is 0.07 or more and 0.60 or less, where b is a cross-sectional area of a connecting portion between one tire circumferential direction side end portion of the shoulder-side circumferential direction groove and the lug groove, and c is a cross-sectional area of the lug groove at the contact edge, and wherein the contact edge is the tire width direction outermost position of a portion of a tread face that contacts the road surface when the pneumatic tire is mounted to a standard rim, as defined in the standard in the location of use or manufacturing location, inflated to an internal pressure of 100% the air pressure corresponding to the maximum load capacity for the applicable standard size/ply rating, when the maximum load capacity is applied thereto. a tread that contacts a road surface; and a plurality of grooves (14, 16, 20) that are provided at the tread and that partition a land portion, wherein, taking a groove side-wall to 1/2 the depth of the groove from a tread face of the tread as a first groove side-wall (16Fa, 16Ka), and taking a groove side-wall from 1/2 the groove depth to a deepest portion of a groove bottom as a second groove side-wall (16Fb, 16 Kb), A is less than B, wherein the plurality of grooves (14, 16, 20) includes a center circumferential direction groove that extends around the tire circumferential direction on a tire equatorial plane, a plurality of lug grooves that extend from the center circumferential direction groove toward contact edges, and a plurality of shoulder-side circumferential direction grooves that are formed on both tire width direction sides of the center circumferential direction groove so as to couple together one lug groove and another lug groove that are adjacent to each other in the tire circumferential direction, wherein A is an area, when viewed in a cross-section orthogonal to a length direction of the groove, of a region enclosed by a first imaginary line (FL3, FL7) passing through an end portion on a tread face side of the first groove side-wall (16Fa, 16Ka) and perpendicular to the tread face, by a second imaginary line passing through an end portion on a groove bottom side of the first groove side-wall and orthogonal to the first imaginary line (FL3, FL7), and by the first groove side-wall (16Fa, 16Ka), and B is an area, when viewed in a cross-section orthogonal to the length direction of the groove, of a region enclosed by a third imaginary line (FL4, FL8) passing through an end portion on the groove bottom side of the first groove side-wall (16Fa, 16Ka) and perpendicular to the tread face, by a fourth imaginary line passing through the deepest portion of the groove bottom and parallel to the tread face, and by the second groove side-wall (16Fb, 16Kb), wherein a ratio b/c is 0.07 or more and 0.60 or less, where b is a cross-sectional area of a connecting portion between one tire circumferential direction side end portion of the shoulder-side circumferential direction groove and the lug groove, and c is a cross-sectional area of the lug groove at the contact edge, and wherein the contact edge is the tire width direction outermost position of a portion of a tread face that contacts the road surface when the pneumatic tire is mounted to a standard rim, as defined in the standard in the location of use or manufacturing location, inflated to an internal pressure of 100% the air pressure corresponding to the maximum load capacity for the applicable standard size/ply rating, when the maximum load capacity is applied thereto.