diff --git a/src/calibre/srv/metadata.py b/src/calibre/srv/metadata.py
index e3355d7c76..010acd54bb 100644
--- a/src/calibre/srv/metadata.py
+++ b/src/calibre/srv/metadata.py
@@ -24,7 +24,7 @@ from calibre.library.field_metadata import category_icon_map
 from polyglot.builtins import iteritems, itervalues, range, filter, unicode_type
 from polyglot.urllib import quote
 
-IGNORED_FIELDS = frozenset('cover ondevice path marked au_map size'.split())
+IGNORED_FIELDS = frozenset('cover ondevice path marked au_map'.split())
 
 
 def encode_datetime(dateval):
diff --git a/src/pyj/book_list/custom_list.pyj b/src/pyj/book_list/custom_list.pyj
index 1b44260911..504b1a38ce 100644
--- a/src/pyj/book_list/custom_list.pyj
+++ b/src/pyj/book_list/custom_list.pyj
@@ -135,6 +135,20 @@ def render_field(field, mi, book_id):  # {{{
                 val = 1
             return fmt_sidx(val, use_roman=interface_data.use_roman_numerals_for_series_number)
 
+    def process_size(field, fm, name, val):
+        val = val or 0
+        mb = 1024 * 1024
+
+        def fmt(val, suffix):
+            ans = f'{val:.1f}'
+            if ans.endsWith('.0'):
+                ans = ans[:-2]
+            return ans + suffix
+
+        if val < mb:
+            return fmt(val / 1024, 'KB')
+        return fmt(val / mb, 'MB')
+
     name = fm.name or field
     datatype = fm.datatype
     if field is 'comments' or datatype is 'comments':
@@ -160,6 +174,8 @@ def render_field(field, mi, book_id):  # {{{
         func = process_series
     elif field.endswith('_index'):
         func = process_series_index
+    elif field is 'size':
+        func = process_size
     ans = None
     if func:
         ans = func(field, fm, name, val)