diff --git a/sumpy/expansion/__init__.py b/sumpy/expansion/__init__.py
index c1281f9691613ffcb5c3e8ab4a50e7ce7e3bd3da..280eb8b791407c57f2472c52b71445bd4f635486 100644
--- a/sumpy/expansion/__init__.py
+++ b/sumpy/expansion/__init__.py
@@ -122,6 +122,15 @@ class VolumeTaylorExpansionBase(object):
         """
         raise NotImplementedError
 
+    @property
+    @memoize_method
+    def _storage_loc_dict(self):
+        return dict((i, idx) for idx, i in
+                    enumerate(self.get_coefficient_identifiers()))
+
+    def get_storage_index(self, i):
+        return self._storage_loc_dict[i]
+
     @memoize_method
     def get_full_coefficient_identifiers(self):
         """