Index: tool/spaceanal.tcl
==================================================================
--- tool/spaceanal.tcl
+++ tool/spaceanal.tcl
@@ -422,19 +422,24 @@
   # payload_percent: Payload bytes used as a percentage of $storage.
   # total_unused: Unused bytes on pages.
   # avg_payload: Average payload per btree entry.
   # avg_fanout: Average fanout for internal pages.
   # avg_unused: Average unused bytes per btree entry.
+  # avg_meta: Average metadata overhead per entry.
   # ovfl_cnt_percent: Percentage of btree entries that use overflow pages.
   #
   set total_pages [expr {$leaf_pages+$int_pages+$ovfl_pages}]
   set total_pages_percent [percent $total_pages $file_pgcnt]
   set storage [expr {$total_pages*$pageSize}]
   set payload_percent [percent $payload $storage {of storage consumed}]
   set total_unused [expr {$ovfl_unused+$int_unused+$leaf_unused}]
   set avg_payload [divide $payload $nentry]
   set avg_unused [divide $total_unused $nentry]
+  set total_meta [expr {$storage - $payload - $total_unused}]
+  set total_meta [expr {$total_meta + 4*($ovfl_pages - $ovfl_cnt)}]
+  set meta_percent [percent $total_meta $storage {of metadata}]
+  set avg_meta [divide $total_meta $nentry]
   if {$int_pages>0} {
     # TODO: Is this formula correct?
     set nTab [mem eval "
       SELECT count(*) FROM (
           SELECT DISTINCT tblname FROM space_used WHERE $where AND is_index=0
@@ -458,13 +463,15 @@
     set pct [expr {$compressed_size*100.0/$storage}]
     set pct [format {%5.1f%%} $pct]
     statline {Bytes used after compression} $compressed_size $pct
   }
   statline {Bytes of payload} $payload $payload_percent
+  statline {Bytes of metadata} $total_meta $meta_percent
   if {$cnt==1} {statline {B-tree depth} $depth}
   statline {Average payload per entry} $avg_payload
   statline {Average unused bytes per entry} $avg_unused
+  statline {Average metadata per entry} $avg_meta
   if {[info exists avg_fanout]} {
     statline {Average fanout} $avg_fanout
   }
   if {$showFrag && $total_pages>1} {
     set fragmentation [percent $gap_cnt [expr {$total_pages-1}]]
@@ -755,10 +762,19 @@
     The amount of payload stored under this category.  Payload is the data
     part of table entries and the key part of index entries.  The percentage
     at the right is the bytes of payload divided by the bytes of storage 
     consumed.
 
+Bytes of metadata
+
+    The amount of formatting and structural information stored on for the
+    table or index.  Metadata includes the btree page header, the cell pointer
+    array, the size field for each cell, the left child pointer or non-leaf
+    cells, the overflow pointers for overflow cells, and the rowid value for
+    rowid table cells.  In other words, metadata is everything that is not
+    unused space and that is not content.
+
 Average payload per entry
 
     The average amount of payload on each entry.  This is just the bytes of
     payload divided by the number of entries.