diff --git a/csppfetch/__init__.py b/csppfetch/__init__.py
index 94e6b87356c844cb70321af9ea50b7d891883826..fa1e10092c884d8f69faeb3054238866577ea1ef 100644
--- a/csppfetch/__init__.py
+++ b/csppfetch/__init__.py
@@ -96,21 +96,45 @@ class FileSet:
 
 
 def human_bytes(total_bytes):
+    """ return nicely formatted string for a count of bytes
+
+    The result is rounded to the displayed precision,
+    so (1024**2)-512 is "1.00 MiB" but (1024**2)-513 is "1023 KiB"
+
+    >>> human_bytes(0)
+    '0 B'
+    >>> human_bytes(3836163)
+    '3.66 MiB'
+    >>> human_bytes((1024**2)-512)
+    '1.00 MiB'
+    >>> human_bytes((1024**2)-513)
+    '1023 KiB'
+    >>> human_bytes(7763153400)
+    '7.23 GiB'
+    """
     step_size = 1024
+    # Yes, it's "Ki", not "ki".
     steps = "Ki Mi Gi Ti Pi Ei".split()
     # If you prefer the non-binary SI prefixes
     # step_size = 1000
-    #     steps = [""]+list("kMGTPE")
+    # steps = "kMGTPE"
     if total_bytes < step_size:
         return f"{total_bytes} B"
     value = total_bytes
     step = -1
-    while value >= step_size:
+    while round(value,0) >= step_size:
         step += 1
         value /= step_size
-    value_str = f"{value:f}"[:4]
-    if value_str[-1] == ".":
-        value_str = value_str[:-1]
+
+    if round(value, 2) < 10:
+        value = round(value, 2)
+        value_str = f"{value:.2f}"
+    elif round(value, 1) < 100:
+        value = round(value, 1)
+        value_str = f"{value:.1f}"
+    else:
+        value = round(value, 0)
+        value_str = f"{value:.0f}"
 
     return f"{value_str} {steps[step]}B"
 
diff --git a/csppfetch/test.py b/csppfetch/test.py
index 787786280a0e7da9c4033dfd37302c7a404b4c1f..fc5de6e9c6f9a7aa07295fb7be911eabdb33d697 100755
--- a/csppfetch/test.py
+++ b/csppfetch/test.py
@@ -708,6 +708,7 @@ def load_tests(loader, tests, ignore):
         'Downloader': csppfetch.Downloader,
         'FileSet': csppfetch.FileSet,
         'ShadowEnvironment': ShadowEnvironment,
+        'human_bytes': csppfetch.human_bytes,
 
         # Functions
         'download_all': csppfetch.download_all,