Small-strain　shear　modulus　(G(0))　is　a　fundamental　property　required　in　dynamic　analyses.　For　sandy　soils,　G(0)　may　be　affected　strongly　by　particle　characteristics　such　as　uniformity　coefficient　(C-u),　mean　particle　size　(d(50)),　fines　content　(FC),　and　particle　shape.　Based　on　an　extensive　experimental　study　of　the　mechanical　behavior　of　coral　sands,　this　paper　proposes　a　new　formula　for　predicting　G(0)　for　sandy　soils　with　various　C-u,　d(50),　FC,　and　particle　shapes.　A　notable　feature　of　the　new　formula　is　the　use　of　the　extreme　void　ratios　(maximum　void　ratio　e(max)　and　minimum　void　ratio　emin)　as　the　indexes,　which　were　shown　to　be　able　to　account　for　the　effects　of　the　various　factors　in　a　simple　yet　collective　manner.　Power-law　correlations　were　established　between　the　minimum　small-strain　shear　modulus　G(0min)　and　e(max)　as　well　as　between　the　maximum　small-strain　shear　modulus　G(0max)　and　emin.　The　wide　applicability　of　this　formula　was　validated　further　using　extensive　data　from　the　literature　from　resonant　column,　bender　element,　and　torsional　shear　tests　on　siliceous,　calcareous,　and　coral　sandy　soils.