diff --git a/v2/storagegroup/convert.go b/v2/storagegroup/convert.go
new file mode 100644
index 0000000..4e45e34
--- /dev/null
+++ b/v2/storagegroup/convert.go
@@ -0,0 +1,53 @@
+package storagegroup
+
+import (
+	"github.com/nspcc-dev/neofs-api-go/v2/refs"
+	refsGRPC "github.com/nspcc-dev/neofs-api-go/v2/refs/grpc"
+	sg "github.com/nspcc-dev/neofs-api-go/v2/storagegroup/grpc"
+)
+
+func StorageGroupToGRPCMessage(s *StorageGroup) *sg.StorageGroup {
+	if s == nil {
+		return nil
+	}
+
+	m := new(sg.StorageGroup)
+
+	m.SetValidationDataSize(s.GetValidationDataSize())
+	m.SetValidationHash(s.GetValidationHash())
+	m.SetExpirationEpoch(s.GetExpirationEpoch())
+
+	members := s.GetMembers()
+	memberMsg := make([]*refsGRPC.ObjectID, 0, len(members))
+
+	for i := range members {
+		memberMsg = append(memberMsg, refs.ObjectIDToGRPCMessage(members[i]))
+	}
+
+	m.SetMembers(memberMsg)
+
+	return m
+}
+
+func StorageGroupFromGRPCMessage(m *sg.StorageGroup) *StorageGroup {
+	if m == nil {
+		return nil
+	}
+
+	s := new(StorageGroup)
+
+	s.SetValidationDataSize(m.GetValidationDataSize())
+	s.SetValidationHash(m.GetValidationHash())
+	s.SetExpirationEpoch(m.GetExpirationEpoch())
+
+	memberMsg := m.GetMembers()
+	members := make([]*refs.ObjectID, 0, len(memberMsg))
+
+	for i := range memberMsg {
+		members = append(members, refs.ObjectIDFromGRPCMessage(memberMsg[i]))
+	}
+
+	s.SetMembers(members)
+
+	return s
+}