diff --git a/src/rez/tests/test_utils_formatting.py b/src/rez/tests/test_utils_formatting.py
new file mode 100644
index 000000000..43ad97345
--- /dev/null
+++ b/src/rez/tests/test_utils_formatting.py
@@ -0,0 +1,36 @@
+# 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")
diff --git a/src/rez/utils/formatting.py b/src/rez/utils/formatting.py
index 87d428909..aa8aad41c 100644
--- a/src/rez/utils/formatting.py
+++ b/src/rez/utils/formatting.py
@@ -364,7 +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)