diff --git a/blog/models.py b/blog/models.py
index 4784562..80b3515 100644
--- a/blog/models.py
+++ b/blog/models.py
@@ -1,4 +1,4 @@
-# -*- coding: utf-8 -*- 
+# -*- coding: utf-8 -*-
 
 from django.db import models
 from django.utils import timezone
@@ -23,14 +23,16 @@ class Post(models.Model):
 
     def __unicode__(self):
         return self.title
-    
+
 
 def font_size(self):
     min_font = 12
     max_font = 28
     v = Tag.objects.all().annotate(c = Count('post')).filter(c__gt = 0).aggregate(Min('c'), Max('c'))
     max_tag, min_tag = v["c__max"], v["c__min"]
-    step = (max_font - min_font)/float(max_tag-min_tag)
+
+    try: step = (max_font - min_font)/float(max_tag-min_tag)
+    except: step = 1
     tag_count = Post.objects.filter(tags__name=self.name).count()
     #print Tag.objects.filter(name=self.name).annotate(c = Count('post'))
     font = int(min_font + (tag_count-min_tag)*step)