Golf ball

A golf ball comprising a core, a mid layer positioned outside the core, and a cover positioned outside the mid layer, wherein

• the golf ball diameter is equal to or greater than 40 mm but equal to or less than 45 mm,
• the core includes an inner core and an outer core positioned outside the inner core,
• the core diameter is equal to or greater than 37.0 mm but equal to or less than 42.0 mm,
• the outer core volume Vr is equal to or greater than 25,500 mm3 but equal to or less than 30,000 mm3,
• the outer core is formed from a crosslinked rubber composition that includes 100 parts by weight of a base rubber and 30 parts by weight or greater but 50 parts by weight or less of a co-crosslinking agent, the inner core is formed from a crosslinked rubber composition that includes 100 parts by weight of a base rubber and 23 parts by weight or greater but 45 parts by weight of less of a co-crosslinking agent, with the inner core co-crosslinking agent amount being at least 5 parts by weight less than that of the outer core,
• the cover includes an inner layer cover and an outer layer cover positioned outside the inner layer cover, and
• when:
• a volume (mm3) of the inner core is defined as Vc;
• a volume (mm3) of the mid layer is defined as Vm;
• a Shore D hardness of the mid layer is defined as Hm;
• a volume (mm3) of the inner layer cover is defined as Vinc;
• a Shore D hardness of the inner layer cover is defined as Hinc;
• a volume (mm3) of the outer layer cover is defined as Vouc;
• a Shore D hardness of the outer layer cover is defined as Houc;
• and
• a volume of the entire ball is defined as V,
• the golf ball meets the following relational expressions (a) to (g):
• 0.02≦Vc/V<0.07, (a)
• Hm>Hinc>Houc, (b)
• Hm−Houc>25, (c)
• Vm>Vine>Vouc, (d)
• (Vm+Vinc+Vouc)/V<0.30, (e)
• Vm/Vouc>1.50, (f)
• and
• (Vm*Hm)/(Vouc*Houc)>3.0. (g)