diff --git a/mercurial/archival.py b/mercurial/archival.py
--- a/mercurial/archival.py
+++ b/mercurial/archival.py
@@ -276,8 +276,11 @@ def archive(repo, dest, node, kind, deco
                         'style': '', 'patch': None, 'git': None}
                 cmdutil.show_changeset(repo.ui, repo, opts).show(ctx)
                 ltags, dist = repo.ui.popbuffer().split('\n')
-                tags = ''.join('latesttag: %s\n' % t for t in ltags.split(':'))
+                ltags = ltags.split(':')
+                changessince = len(repo.revs('only(.,%s)', ltags[0]))
+                tags = ''.join('latesttag: %s\n' % t for t in ltags)
                 tags += 'latesttagdistance: %s\n' % dist
+                tags += 'changessincelatesttag: %s\n' % changessince
 
             return base + tags
 
diff --git a/tests/test-archive.t b/tests/test-archive.t
--- a/tests/test-archive.t
+++ b/tests/test-archive.t
@@ -250,6 +250,7 @@ test .hg_archival.txt
   branch: default
   latesttag: null
   latesttagdistance: 4
+  changessincelatesttag: 4
   $ hg tag -r 2 mytag
   $ hg tag -r 2 anothertag
   $ hg archive -r 2 ../test-lasttag
@@ -322,10 +323,10 @@ old file -- date clamped to 1980
   Archive:  ../old.zip
   \s*Length.* (re)
   *-----* (glob)
-  *147*80*00:00*old/.hg_archival.txt (glob)
+  *172*80*00:00*old/.hg_archival.txt (glob)
   *0*80*00:00*old/old (glob)
   *-----* (glob)
-  \s*147\s+2 files (re)
+  \s*172\s+2 files (re)
 
 show an error when a provided pattern matches no files