diff --git a/app/models/search_term.rb b/app/models/search_term.rb
index f45b22a..d6720ac 100644
--- a/app/models/search_term.rb
+++ b/app/models/search_term.rb
@@ -42,6 +42,7 @@ class SearchTerm < ActiveRecord::Base
 
   def calculate_relevance(valid_occurrences)
     indexed = valid_occurrences.last.indexed.to_f
+    return 0 if indexed == 0
     total = valid_occurrences.last.total.to_f
     (1 - indexed/total)*100
   end
diff --git a/test/unit/search_term_test.rb b/test/unit/search_term_test.rb
index 2fb6284..4a1bba8 100644
--- a/test/unit/search_term_test.rb
+++ b/test/unit/search_term_test.rb
@@ -118,4 +118,12 @@ class SearchTermTest < ActiveSupport::TestCase
 
     assert st1.score > st2.score, "Less ratio results:total are not getting higher scores."
   end
+
+  should 'consider relevance zero if no results indexed' do
+    st = SearchTerm.find_or_create('st', Environment.default)
+    SearchTermOccurrence.create!(:search_term => st, :total => 10, :indexed => 0)
+    SearchTerm.calculate_scores
+    st.reload
+    assert_equal 0, st.score
+  end
 end
--
libgit2 0.21.2