A heavy duty tire having a nominal aspect ratio of not greater than 70%, the tire comprising: a tread; and a reinforcing portion located radially inward of the tread, wherein a plurality of land portions (26, 26c, 26m, 26s) demarcated by a plurality of circumferential grooves (24, 24m, 24s) are formed in the tread, among the plurality of circumferential grooves (24, 24m, 24s), a circumferential groove located on each outer side in an axial direction is a shoulder circumferential groove, among the plurality of land portions (26, 26c, 26m, 26s), a land portion located axially outward of the shoulder circumferential groove is a shoulder land portion, the reinforcing portion includes a belt including a large number of belt cords (44, 44A, 44B, 44C, 44D) aligned with each other, and a band including a helically wound band cord (48, 48F, 48E), the band includes a full band, each of both ends of the full band is located axially outward of the shoulder circumferential groove, the tread has a tread surface which comes into contact with a road surface, in a meridian cross-section, a contour line of the tread surface includes a first contour line including an equator, and a pair of second contour lines connected to the first contour line and each including an end of the tread surface, the first contour line is an arc, each of the pair of second contour lines is a straight line or an arc, when each second contour line is an arc, a radius of curvature of the second contour line is different from a radius of curvature of the first contour line, and in the contour line of the tread surface, a boundary between the first contour line and the second contour line is located in a portion corresponding to the shoulder circumferential groove; characterized in that the band includes a pair of edge bands, the pair of edge bands are disposed so as to be spaced apart from each other in the axial direction, and are each located radially outward of the end of the full band, an outer diameter of the tire at the equator is a first outer diameter D1, an outer diameter of the tire at an inner edge of the shoulder land portion is a second outer diameter D2, an outer diameter of the tire at the end of the tread surface is a third outer diameter D3, and the first outer diameter D1, the second outer diameter D2, and the third outer diameter D3 satisfy the following formulas and, D 1 > D 2 > D 3 0.65 ≤ D 2 − D 3 / D 1 − D 3 ≤ 0.85 a tread; and a reinforcing portion located radially inward of the tread, wherein a plurality of land portions (26, 26c, 26m, 26s) demarcated by a plurality of circumferential grooves (24, 24m, 24s) are formed in the tread, among the plurality of circumferential grooves (24, 24m, 24s), a circumferential groove located on each outer side in an axial direction is a shoulder circumferential groove, among the plurality of land portions (26, 26c, 26m, 26s), a land portion located axially outward of the shoulder circumferential groove is a shoulder land portion, the reinforcing portion includes a belt including a large number of belt cords (44, 44A, 44B, 44C, 44D) aligned with each other, and a band including a helically wound band cord (48, 48F, 48E), the band includes a full band, each of both ends of the full band is located axially outward of the shoulder circumferential groove, the tread has a tread surface which comes into contact with a road surface, in a meridian cross-section, a contour line of the tread surface includes a first contour line including an equator, and a pair of second contour lines connected to the first contour line and each including an end of the tread surface, the first contour line is an arc, each of the pair of second contour lines is a straight line or an arc, when each second contour line is an arc, a radius of curvature of the second contour line is different from a radius of curvature of the first contour line, and in the contour line of the tread surface, a boundary between the first contour line and the second contour line is located in a portion corresponding to the shoulder circumferential groove; the band includes a pair of edge bands, the pair of edge bands are disposed so as to be spaced apart from each other in the axial direction, and are each located radially outward of the end of the full band, an outer diameter of the tire at the equator is a first outer diameter D1, an outer diameter of the tire at an inner edge of the shoulder land portion is a second outer diameter D2, an outer diameter of the tire at the end of the tread surface is a third outer diameter D3, and the first outer diameter D1, the second outer diameter D2, and the third outer diameter D3 satisfy the following formulas and, D 1 > D 2 > D 3 0.65 ≤ D 2 − D 3 / D 1 − D 3 ≤ 0.85