diff --git a/src/calibre/gui2/preferences/create_custom_column.py b/src/calibre/gui2/preferences/create_custom_column.py
index f3fe8f03a3..8eaa2dd7d9 100644
--- a/src/calibre/gui2/preferences/create_custom_column.py
+++ b/src/calibre/gui2/preferences/create_custom_column.py
@@ -182,6 +182,18 @@ class CreateCustomColumn(QDialog, Ui_QCreateCustomColumn):
             getattr(self, 'enum_'+x).setVisible(col_type == 'enumeration')
         self.use_decorations.setVisible(col_type in ['text', 'composite', 'enumeration'])
         self.is_names.setVisible(col_type == '*text')
+        if col_type == 'int':
+            self.number_format_box.setToolTip('<p>' +
+                _('Examples: The format <code>{0:0>4d}</code> '
+                  'gives a 4-digit number with leading zeros. The format '
+                  '<code>{0:d}&nbsp;days</code> prints the number then the word "days"')+ '</p>')
+        elif col_type == 'float':
+            self.number_format_box.setToolTip('<p>' +
+                _('Examples: The format <code>{0:.1f}</code> gives a floating '
+                  'point number with 1 digit after the decimal point. The format '
+                  '<code>Price:&nbsp;$&nbsp;{0:,.2f}</code> prints '
+                  '"Price&nbsp;$&nbsp;" then displays the number with 2 digits '
+                  'after the decimal point and thousands separated by commas.') + '</p>')
 
     def accept(self):
         col = unicode(self.column_name_box.text()).strip()
diff --git a/src/calibre/gui2/preferences/create_custom_column.ui b/src/calibre/gui2/preferences/create_custom_column.ui
index 02daae988f..cedbfd72b8 100644
--- a/src/calibre/gui2/preferences/create_custom_column.ui
+++ b/src/calibre/gui2/preferences/create_custom_column.ui
@@ -179,10 +179,6 @@ Everything else will show nothing.</string>
              <verstretch>0</verstretch>
             </sizepolicy>
            </property>
-           <property name="toolTip">
-            <string>&lt;p&gt;Use 0 (a zero) for the field name. Example: {0:0>5.2f} gives a 5-digit floating point number, 2 digits after the decimal point, with leading zeros
-            </string>
-           </property>
           </widget>
          </item>
          <item>
@@ -198,7 +194,9 @@ Everything else will show nothing.</string>
          <item>
           <widget class="QLabel" name="number_format_default_label">
            <property name="toolTip">
-            <string>&lt;p&gt;Example: ${0:,.2f} gives floating point number prefixed by a dollar sign, 2 digits after the decimal point, with thousands separated by commas</string>
+            <string>&lt;p&gt;The format specifier must begin with &lt;code&gt;{0:&lt;/code&gt;
+and end with &lt;code&gt;}&lt;/code&gt; You can have text before and after the format specifier.
+            </string>
            </property>
            <property name="text">
             <string>&lt;p&gt;Default: Not formatted. For format language details see &lt;a href="http://docs.python.org/library/string.html#format-string-syntax"&gt;the python documentation&lt;/a&gt;</string>