diff --git a/picard/util/bytes2human.py b/picard/util/bytes2human.py
new file mode 100644
index 000000000..7bf1011ad
--- /dev/null
+++ b/picard/util/bytes2human.py
@@ -0,0 +1,125 @@
+# -*- coding: utf-8 -*-
+#
+# Picard, the next-generation MusicBrainz tagger
+# Copyright (C) 2013 Laurent Monin
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+import locale
+import picard.i18n
+
+
+"""
+Helper class to convert bytes to human-readable form
+It supports i18n through gettext, decimal and binary units.
+
+>>> n = 1572864
+>>> [binary(n), decimal(n)]
+['1.5 MiB', '1.6 MB']
+"""
+
+#used to force gettextization
+_BYTES_STRINGS_I18N = (
+    N_('%s B'),
+    N_('%s kB'),
+    N_('%s KiB'),
+    N_('%s MB'),
+    N_('%s MiB'),
+    N_('%s GB'),
+    N_('%s GiB'),
+    N_('%s TB'),
+    N_('%s TiB'),
+    N_('%s PB'),
+    N_('%s PiB'),
+)
+
+
+def decimal(number, prec=1):
+    """
+    Convert bytes to short human-readable string, decimal mode
+
+    >>> [decimal(n) for n in [1000, 1024, 15500]]
+    ['1 kB', '1 kB', '15.5 kB']
+    """
+    return short_string(int(number), 1000)
+
+
+def binary(number, prec=1):
+    """
+    Convert bytes to short human-readable string, binary mode
+    >>> [binary(n) for n in [1000, 1024, 15500]]
+    ['1000 B', '1 KiB', '15.1 KiB']
+    """
+    return short_string(int(number), 1024, prec)
+
+
+def short_string(number, multiple, prec=1):
+    """
+    Returns short human-readable string for `number` bytes
+    >>> [short_string(n, 1024, 2) for n in [1000, 1100, 15500]]
+    ['1000 B', '1.07 KiB', '15.14 KiB']
+    >>> [short_string(n, 1000, 1) for n in [10000, 11000, 1550000]]
+    ['10 kB', '11 kB', '1.6 MB']
+    """
+    num, unit = calc_unit(number, multiple)
+    n = int(num)
+    nr = round(num, prec)
+    if n == nr or unit == 'B':
+        fmt = '%d'
+        num = n
+    else:
+        fmt = '%%0.%df' % prec
+        num = nr
+    fmtnum = locale.format(fmt, num)
+    return _("%s " + unit) % fmtnum
+
+
+def calc_unit(number, multiple=1000):
+    """
+    Calculate rounded number of multiple * bytes, finding best unit
+
+    >>> calc_unit(12456, 1024)
+    (12.1640625, 'KiB')
+    >>> calc_unit(-12456, 1000)
+    (-12.456, 'kB')
+    >>> calc_unit(0, 1001)
+    Traceback (most recent call last):
+        ...
+    ValueError: multiple parameter has to be 1000 or 1024
+    """
+    if number < 0:
+        sign = -1
+        number = -number
+    else:
+        sign = 1
+    n = float(number)
+    if multiple == 1000:
+        k, b = 'k', 'B'
+    elif multiple == 1024:
+        k, b = 'K', 'iB'
+    else:
+        raise ValueError('multiple parameter has to be 1000 or 1024')
+
+    suffixes = ["B"] + [i + b for i in k + "MGTP"]
+    for suffix in suffixes:
+        if n < multiple or suffix == suffixes[-1]:
+            return (sign*n, suffix)
+        else:
+            n /= multiple
+
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()
diff --git a/test/data/b2h_test_C.dat b/test/data/b2h_test_C.dat
new file mode 100644
index 000000000..5693d8825
--- /dev/null
+++ b/test/data/b2h_test_C.dat
@@ -0,0 +1,74 @@
+0;0 B;0 B;0 B
+1;1 B;1 B;1 B
+100;100 B;100 B;100 B
+102;102 B;102 B;102 B
+500;500 B;500 B;500 B
+512;512 B;512 B;512 B
+990;990 B;990 B;990 B
+999;999 B;999 B;999 B
+1000;1 kB;1000 B;1000 B
+1013;1 kB;1013 B;1013 B
+1023;1 kB;1023 B;1023 B
+1024;1 kB;1 KiB;1 KiB
+1500;1.5 kB;1.5 KiB;1.46 KiB
+1536;1.5 kB;1.5 KiB;1.50 KiB
+100000;100 kB;97.7 KiB;97.66 KiB
+104857;104.9 kB;102.4 KiB;102.40 KiB
+500000;500 kB;488.3 KiB;488.28 KiB
+524288;524.3 kB;512 KiB;512 KiB
+990000;990 kB;966.8 KiB;966.80 KiB
+999900;999.9 kB;976.5 KiB;976.46 KiB
+1000000;1 MB;976.6 KiB;976.56 KiB
+1038090;1 MB;1013.8 KiB;1013.76 KiB
+1048471;1 MB;1023.9 KiB;1023.90 KiB
+1048576;1 MB;1 MiB;1 MiB
+1500000;1.5 MB;1.4 MiB;1.43 MiB
+1572864;1.6 MB;1.5 MiB;1.50 MiB
+100000000;100 MB;95.4 MiB;95.37 MiB
+107374182;107.4 MB;102.4 MiB;102.40 MiB
+500000000;500 MB;476.8 MiB;476.84 MiB
+536870912;536.9 MB;512 MiB;512 MiB
+990000000;990 MB;944.1 MiB;944.14 MiB
+999900000;999.9 MB;953.6 MiB;953.58 MiB
+1000000000;1 GB;953.7 MiB;953.67 MiB
+1063004405;1.1 GB;1013.8 MiB;1013.76 MiB
+1073634449;1.1 GB;1023.9 MiB;1023.90 MiB
+1073741824;1.1 GB;1 GiB;1 GiB
+1500000000;1.5 GB;1.4 GiB;1.40 GiB
+1610612736;1.6 GB;1.5 GiB;1.50 GiB
+100000000000;100 GB;93.1 GiB;93.13 GiB
+109951162777;110.0 GB;102.4 GiB;102.40 GiB
+500000000000;500 GB;465.7 GiB;465.66 GiB
+549755813888;549.8 GB;512 GiB;512 GiB
+990000000000;990 GB;922 GiB;922.01 GiB
+999900000000;999.9 GB;931.2 GiB;931.23 GiB
+1000000000000;1 TB;931.3 GiB;931.32 GiB
+1088516511498;1.1 TB;1013.8 GiB;1013.76 GiB
+1099401676613;1.1 TB;1023.9 GiB;1023.90 GiB
+1099511627776;1.1 TB;1 TiB;1 TiB
+1500000000000;1.5 TB;1.4 TiB;1.36 TiB
+1649267441664;1.6 TB;1.5 TiB;1.50 TiB
+100000000000000;100 TB;90.9 TiB;90.95 TiB
+112589990684262;112.6 TB;102.4 TiB;102.40 TiB
+500000000000000;500 TB;454.7 TiB;454.75 TiB
+562949953421312;562.9 TB;512 TiB;512 TiB
+990000000000000;990 TB;900.4 TiB;900.40 TiB
+999900000000000;999.9 TB;909.4 TiB;909.40 TiB
+1000000000000000;1 PB;909.5 TiB;909.49 TiB
+1114640907774197;1.1 PB;1013.8 TiB;1013.76 TiB
+1125787316851939;1.1 PB;1023.9 TiB;1023.90 TiB
+1125899906842624;1.1 PB;1 PiB;1 PiB
+1500000000000000;1.5 PB;1.3 PiB;1.33 PiB
+1688849860263936;1.7 PB;1.5 PiB;1.50 PiB
+100000000000000000;100 PB;88.8 PiB;88.82 PiB
+115292150460684704;115.3 PB;102.4 PiB;102.40 PiB
+500000000000000000;500 PB;444.1 PiB;444.09 PiB
+576460752303423488;576.5 PB;512 PiB;512 PiB
+990000000000000000;990 PB;879.3 PiB;879.30 PiB
+999900000000000000;999.9 PB;888.1 PiB;888.09 PiB
+1000000000000000000;1000 PB;888.2 PiB;888.18 PiB
+1141392289560778496;1141.4 PB;1013.8 PiB;1013.76 PiB
+1152806212456386304;1152.8 PB;1023.9 PiB;1023.90 PiB
+1152921504606846976;1152.9 PB;1024 PiB;1024 PiB
+1500000000000000000;1500 PB;1332.3 PiB;1332.27 PiB
+1729382256910270464;1729.4 PB;1536 PiB;1536 PiB
diff --git a/test/data/b2h_test_fr_FR.UTF-8.dat b/test/data/b2h_test_fr_FR.UTF-8.dat
new file mode 100644
index 000000000..f781da84e
--- /dev/null
+++ b/test/data/b2h_test_fr_FR.UTF-8.dat
@@ -0,0 +1,74 @@
+0;0 o;0 o;0 o
+1;1 o;1 o;1 o
+100;100 o;100 o;100 o
+102;102 o;102 o;102 o
+500;500 o;500 o;500 o
+512;512 o;512 o;512 o
+990;990 o;990 o;990 o
+999;999 o;999 o;999 o
+1000;1 ko;1000 o;1000 o
+1013;1 ko;1013 o;1013 o
+1023;1 ko;1023 o;1023 o
+1024;1 ko;1 Kio;1 Kio
+1500;1,5 ko;1,5 Kio;1,46 Kio
+1536;1,5 ko;1,5 Kio;1,50 Kio
+100000;100 ko;97,7 Kio;97,66 Kio
+104857;104,9 ko;102,4 Kio;102,40 Kio
+500000;500 ko;488,3 Kio;488,28 Kio
+524288;524,3 ko;512 Kio;512 Kio
+990000;990 ko;966,8 Kio;966,80 Kio
+999900;999,9 ko;976,5 Kio;976,46 Kio
+1000000;1 Mo;976,6 Kio;976,56 Kio
+1038090;1 Mo;1013,8 Kio;1013,76 Kio
+1048471;1 Mo;1023,9 Kio;1023,90 Kio
+1048576;1 Mo;1 Mio;1 Mio
+1500000;1,5 Mo;1,4 Mio;1,43 Mio
+1572864;1,6 Mo;1,5 Mio;1,50 Mio
+100000000;100 Mo;95,4 Mio;95,37 Mio
+107374182;107,4 Mo;102,4 Mio;102,40 Mio
+500000000;500 Mo;476,8 Mio;476,84 Mio
+536870912;536,9 Mo;512 Mio;512 Mio
+990000000;990 Mo;944,1 Mio;944,14 Mio
+999900000;999,9 Mo;953,6 Mio;953,58 Mio
+1000000000;1 Go;953,7 Mio;953,67 Mio
+1063004405;1,1 Go;1013,8 Mio;1013,76 Mio
+1073634449;1,1 Go;1023,9 Mio;1023,90 Mio
+1073741824;1,1 Go;1 Gio;1 Gio
+1500000000;1,5 Go;1,4 Gio;1,40 Gio
+1610612736;1,6 Go;1,5 Gio;1,50 Gio
+100000000000;100 Go;93,1 Gio;93,13 Gio
+109951162777;110,0 Go;102,4 Gio;102,40 Gio
+500000000000;500 Go;465,7 Gio;465,66 Gio
+549755813888;549,8 Go;512 Gio;512 Gio
+990000000000;990 Go;922 Gio;922,01 Gio
+999900000000;999,9 Go;931,2 Gio;931,23 Gio
+1000000000000;1 To;931,3 Gio;931,32 Gio
+1088516511498;1,1 To;1013,8 Gio;1013,76 Gio
+1099401676613;1,1 To;1023,9 Gio;1023,90 Gio
+1099511627776;1,1 To;1 Tio;1 Tio
+1500000000000;1,5 To;1,4 Tio;1,36 Tio
+1649267441664;1,6 To;1,5 Tio;1,50 Tio
+100000000000000;100 To;90,9 Tio;90,95 Tio
+112589990684262;112,6 To;102,4 Tio;102,40 Tio
+500000000000000;500 To;454,7 Tio;454,75 Tio
+562949953421312;562,9 To;512 Tio;512 Tio
+990000000000000;990 To;900,4 Tio;900,40 Tio
+999900000000000;999,9 To;909,4 Tio;909,40 Tio
+1000000000000000;1 Po;909,5 Tio;909,49 Tio
+1114640907774197;1,1 Po;1013,8 Tio;1013,76 Tio
+1125787316851939;1,1 Po;1023,9 Tio;1023,90 Tio
+1125899906842624;1,1 Po;1 Pio;1 Pio
+1500000000000000;1,5 Po;1,3 Pio;1,33 Pio
+1688849860263936;1,7 Po;1,5 Pio;1,50 Pio
+100000000000000000;100 Po;88,8 Pio;88,82 Pio
+115292150460684704;115,3 Po;102,4 Pio;102,40 Pio
+500000000000000000;500 Po;444,1 Pio;444,09 Pio
+576460752303423488;576,5 Po;512 Pio;512 Pio
+990000000000000000;990 Po;879,3 Pio;879,30 Pio
+999900000000000000;999,9 Po;888,1 Pio;888,09 Pio
+1000000000000000000;1000 Po;888,2 Pio;888,18 Pio
+1141392289560778496;1141,4 Po;1013,8 Pio;1013,76 Pio
+1152806212456386304;1152,8 Po;1023,9 Pio;1023,90 Pio
+1152921504606846976;1152,9 Po;1024 Pio;1024 Pio
+1500000000000000000;1500 Po;1332,3 Pio;1332,27 Pio
+1729382256910270464;1729,4 Po;1536 Pio;1536 Pio
diff --git a/test/po/fr.po b/test/po/fr.po
new file mode 100644
index 000000000..1f58b585b
--- /dev/null
+++ b/test/po/fr.po
@@ -0,0 +1,69 @@
+msgid ""
+msgstr ""
+"Project-Id-Version: MusicBrainz\n"
+"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
+"POT-Creation-Date: 2013-01-20 13:23+0100\n"
+"PO-Revision-Date: 2013-01-20 13:26+0100\n"
+"Last-Translator: Laurent Monin <i18n@norz.org>\n"
+"Language-Team: French (http://www.transifex.com/projects/p/musicbrainz/language/fr/)\n"
+"Language: fr\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Generated-By: Babel 0.9.6\n"
+"Plural-Forms: nplurals=2; plural=(n > 1);\n"
+
+#: picard/util/bytes2human.py:47
+#, python-format
+msgid "%s B"
+msgstr "%s o"
+
+#: picard/util/bytes2human.py:48
+#, python-format
+msgid "%s kB"
+msgstr "%s ko"
+
+#: picard/util/bytes2human.py:49
+#, python-format
+msgid "%s KiB"
+msgstr "%s Kio"
+
+#: picard/util/bytes2human.py:50
+#, python-format
+msgid "%s MB"
+msgstr "%s Mo"
+
+#: picard/util/bytes2human.py:51
+#, python-format
+msgid "%s MiB"
+msgstr "%s Mio"
+
+#: picard/util/bytes2human.py:52
+#, python-format
+msgid "%s GB"
+msgstr "%s Go"
+
+#: picard/util/bytes2human.py:53
+#, python-format
+msgid "%s GiB"
+msgstr "%s Gio"
+
+#: picard/util/bytes2human.py:54
+#, python-format
+msgid "%s TB"
+msgstr "%s To"
+
+#: picard/util/bytes2human.py:55
+#, python-format
+msgid "%s TiB"
+msgstr "%s Tio"
+
+#: picard/util/bytes2human.py:56
+#, python-format
+msgid "%s PB"
+msgstr "%s Po"
+
+#: picard/util/bytes2human.py:57
+#, python-format
+msgid "%s PiB"
+msgstr "%s Pio"
diff --git a/test/test_bytes2human.py b/test/test_bytes2human.py
new file mode 100644
index 000000000..06038bb41
--- /dev/null
+++ b/test/test_bytes2human.py
@@ -0,0 +1,99 @@
+import locale
+import os.path
+import shutil
+import subprocess
+import sys
+import tempfile
+import unittest
+
+from picard.i18n import setup_gettext
+from picard.util import bytes2human
+
+class Testbytes2human(unittest.TestCase):
+    def setUp(self):
+        # we are using temporary locales for tests
+        self.tmp_path = tempfile.mkdtemp().decode("utf-8")
+        if sys.hexversion >= 0x020700F0:
+            self.addCleanup(shutil.rmtree, self.tmp_path)
+        self.localedir = os.path.join(self.tmp_path, 'locale')
+
+        test_locales = [('picard', 'fr', 'test/po/fr.po')]
+        for domain, locale, po in test_locales:
+            path = os.path.join(self.localedir, locale, 'LC_MESSAGES')
+            os.makedirs(path)
+            mo = os.path.join(path, '%s.mo' % domain)
+            assert(subprocess.call(['msgfmt', '-o', mo, po]) == 0)
+
+    def tearDown(self):
+        if sys.hexversion < 0x020700F0:
+            shutil.rmtree(self.tmp_path)
+
+    def test_00(self):
+        # testing with default C locale, english
+        lang = 'C'
+        setup_gettext(self.localedir, lang)
+        self.run_test(lang)
+
+        self.assertEqual(bytes2human.binary(45682), '44.6 KiB')
+        self.assertEqual(bytes2human.binary(-45682), '-44.6 KiB')
+        self.assertEqual(bytes2human.decimal(45682), '45.7 kB')
+        self.assertEqual(bytes2human.decimal(9223372036854775807), '9223.4 PB')
+        self.assertEqual(bytes2human.decimal(123.6), '123 B')
+        self.assertRaises(ValueError, bytes2human.decimal, 'xxx')
+        self.assertRaises(ValueError, bytes2human.decimal, '123.6')
+        self.assertRaises(ValueError, bytes2human.binary, 'yyy')
+        self.assertRaises(ValueError, bytes2human.binary, '456yyy')
+        try:
+            bytes2human.decimal(u'123')
+        except Exception as e:
+            self.fail('Unexpected exception: %s' % e)
+
+    def test_05(self):
+        # testing with french locale and translation
+        # 1.5 MiB -> 1,5 Mio
+        lang = 'fr_FR.UTF-8'
+        setup_gettext(self.localedir, lang)
+        self.run_test(lang)
+
+    def run_test(self, lang = 'C', create_test_data=False):
+        """
+        Compare data generated with sample files
+        Setting create_test_data to True will generated sample files
+        from code execution (developper-only, check carefully)
+        """
+        filename = os.path.join('test', 'data', 'b2h_test_%s.dat' % lang)
+        testlist = self._create_testlist()
+        if create_test_data:
+            self._save_expected_to(filename, testlist)
+        expected = self._read_expected_from(filename)
+        #self.maxDiff = None
+        self.assertEqual(testlist, expected)
+        if create_test_data:
+            # be sure it is disabled
+            self.fail('!!! UNSET create_test_data mode !!! (%s)' % filename)
+
+    def _create_testlist(self):
+        values = [0, 1]
+        for n in [1000, 1024]:
+            p = 1
+            for e in range(0,6):
+                p *= n
+                for x in [0.1, 0.5, 0.99, 0.9999, 1, 1.5]:
+                    values.append(int(p*x))
+        l = []
+        for x in sorted(values):
+            l.append(";".join([str(x), bytes2human.decimal(x),
+                               bytes2human.binary(x),
+                               bytes2human.short_string(x, 1024, 2)]))
+        return l
+
+    def _save_expected_to(self, path, a_list):
+        with open(path, 'wb') as f:
+            f.writelines([l + "\n" for l in a_list])
+            f.close()
+
+    def _read_expected_from(self, path):
+        with open(path, 'rb') as f:
+            lines = [l.rstrip("\n") for l in f.readlines()]
+            f.close()
+            return lines