diff --git a/src/rez/tests/test_utils_formatting.py b/src/rez/tests/test_utils_formatting.py
new file mode 100644
index 000000000..a63388f3c
--- /dev/null
+++ b/src/rez/tests/test_utils_formatting.py
@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright Contributors to the Rez Project
+
+
+"""
+unit tests for 'utils.formatting' module
+"""
+from rez.tests.util import TestBase
+from rez.utils import formatting
+
+
+class TestFormatting(TestBase):
+    def test_readable_units(self):
+        readable_units = formatting._readable_units(
+            0,
+            formatting.memory_divs
+        )
+        self.assertEqual(readable_units, "0 bytes")
+
+        readable_units = formatting._readable_units(
+            1024,
+            formatting.memory_divs
+        )
+        self.assertEqual(readable_units, "1 Kb")
+
+        readable_units = formatting._readable_units(
+            1200,
+            formatting.memory_divs
+        )
+        self.assertEqual(readable_units, "1.2 Kb")
+
+        readable_units = formatting._readable_units(
+            -30000,
+            formatting.memory_divs
+        )
+        self.assertEqual(readable_units, "-29 Kb")
+
+        readable_units = formatting._readable_units(
+            1024,
+            formatting.memory_divs,
+            plural_aware=True
+        )
+        self.assertEqual(readable_units, "1 K")
diff --git a/src/rez/utils/formatting.py b/src/rez/utils/formatting.py
index 3f9c3587d..aa8aad41c 100644
--- a/src/rez/utils/formatting.py
+++ b/src/rez/utils/formatting.py
@@ -10,6 +10,7 @@
 from rez.exceptions import PackageRequestError
 from pprint import pformat
 from enum import Enum
+import math
 import os
 import os.path
 import re
@@ -363,7 +364,9 @@ def readable_time_duration(secs):
 
 
 def readable_memory_size(bytes_):
-    """Convert number of bytes into human readable form, eg '1.2 Kb'.
+    """Convert number of bytes into human-readable form.
+
+    This method rounds to 1 decimal place eg '1.2 Kb'.
     """
     return _readable_units(bytes_, memory_divs)
 
@@ -382,7 +385,8 @@ def _readable_units(value, divs, plural_aware=False):
             rounding = 0 if f > threshold else 1
             f = round(f, rounding)
             f = int(f * 10) / 10.0
-            if plural_aware and f == 1.0:
+            is_one = math.isclose(f, 1.0, rel_tol=1e-09, abs_tol=1e-09)
+            if plural_aware and is_one:
                 unit = unit[:-1]
             txt = "%g %s" % (f, unit)
             break