diff --git a/app/models/version.rb b/app/models/version.rb
index bc71b72..28f63b6 100644
--- a/app/models/version.rb
+++ b/app/models/version.rb
@@ -274,9 +274,11 @@ class Version < ActiveRecord::Base
   # Used to weight unestimated issues in progress calculation
   def estimated_average
     if @estimated_average.nil?
-      average = fixed_issues.average(:estimated_hours).to_f
-      if average == 0
-        average = 1
+      issues_with_total_estimated_hours = fixed_issues.select {|c| c.total_estimated_hours.to_f > 0.0}
+      if issues_with_total_estimated_hours.any?
+        average = issues_with_total_estimated_hours.map(&:total_estimated_hours).sum.to_f / issues_with_total_estimated_hours.count
+      else
+        average = 1.0
       end
       @estimated_average = average
     end
@@ -294,9 +296,13 @@ class Version < ActiveRecord::Base
     @issues_progress[open] ||= begin
       progress = 0
       if issues_count > 0
-        ratio = open ? 'done_ratio' : 100
+        done = fixed_issues.open(open).map {|c|
+              estimated = c.total_estimated_hours.to_f
+              estimated = estimated_average unless estimated > 0.0
+              ratio = c.closed? ? 100 : (c.done_ratio || 0)
+              estimated * ratio
+            }.sum
 
-        done = fixed_issues.open(open).sum("COALESCE(estimated_hours, #{estimated_average}) * #{ratio}").to_f
         progress = done / (estimated_average * issues_count)
       end
       progress