Wheel Bearing Device

A wheel bearing device includes: an inner shaft; an inner ring; an outer ring; and first and second rolling element groups. The first rolling element group is disposed on the vehicle outer side. The second rolling element group is disposed on the vehicle inner side. The first and second rolling element groups have the same contact angle and the same number of balls. A relationship between a ball diameter D1 of the first rolling element group and a ball diameter D2 of the second rolling element group is set such that an inequality D1 > D2 is satisfied. A relationship between a pitch circle diameter PCD1 of the first rolling element group and a pitch circle diameter PCD2 of the second rolling element group is set such that an equation PCD1 = D1 / D2 x PCD2 is satisfied.