HEAVY DUTY PNEUMATIC TIRE

A heavy duty pneumatic tire (1) is allowed to have a weight reduced without reducing durability of beads, and includes: a tread (2); a pair of sidewalls (3); a pair of beads (4); and a clinch portion (5) that extends from the sidewalls (3) to the beads (4), in which a concave curved surface (21) extends on an outer surface of the clinch portion (5) in a circumferential direction, and a convex curved surface (22) formed on an outer side end, in the radial direction, of a rim flange (30) is engageable with the concave curved surface (21), a ratio R1/R2 of a radius of curvature R1 of the concave curved surface (21) to a radius of curvature R2 of the convex curved surface (22) of the rim flange, satisfies 1.7 ¤ R1/R2 ¤ 3.9, a ratio D1 /R2 of a depth D1 of the concave curved surface to the radius of curvature R2 of the convex curved surface satisfies 0.05 ¤ D1/R2 ¤ 0.09, and the radius of curvature R1 of the concave curved surface (21) and the radius of curvature R2 of the convex curved surface (22) are each a radius of curvature of an arc on a cross section as taken along a plane including a center axis of the tire.