diff --git a/gramps/gen/config.py b/gramps/gen/config.py
index 2c3523670..ee655d873 100644
--- a/gramps/gen/config.py
+++ b/gramps/gen/config.py
@@ -282,6 +282,8 @@ register('interface.place-ref-width', 600)
 register('interface.place-sel-height', 450)
 register('interface.place-sel-width', 600)
 register('interface.place-width', 650)
+register('interface.relcalc-height', 400)
+register('interface.relcalc-width', 600)
 register('interface.repo-height', 450)
 register('interface.repo-ref-height', 450)
 register('interface.repo-ref-width', 600)
diff --git a/gramps/plugins/tool/relcalc.glade b/gramps/plugins/tool/relcalc.glade
index e954187c7..cda7894cd 100644
--- a/gramps/plugins/tool/relcalc.glade
+++ b/gramps/plugins/tool/relcalc.glade
@@ -5,8 +5,6 @@
   <object class="GtkDialog" id="relcalc">
     <property name="visible">False</property>
     <property name="can_focus">False</property>
-    <property name="default_width">600</property>
-    <property name="default_height">400</property>
     <property name="type_hint">dialog</property>
     <signal name="delete-event" handler="on_delete_event" swapped="no"/>
     <child internal-child="vbox">
diff --git a/gramps/plugins/tool/relcalc.py b/gramps/plugins/tool/relcalc.py
index a4840a5cf..f911e4a69 100644
--- a/gramps/plugins/tool/relcalc.py
+++ b/gramps/plugins/tool/relcalc.py
@@ -111,6 +111,9 @@ class RelCalc(tool.Tool, ManagedWindow):
                         _('Relationship to %(person_name)s'
                           ) % {'person_name' : name},
                         self.title)
+        self.height_key = 'interface.relcalc-height'
+        self.width_key = 'interface.relcalc-width'
+        self._set_size()
 
         self.tree = self.glade.get_object("peopleList")
         self.text = self.glade.get_object("text1")