diff --git a/conans/client/command.py b/conans/client/command.py
index 9c492eebd95..a304b20c202 100644
--- a/conans/client/command.py
+++ b/conans/client/command.py
@@ -1423,8 +1423,10 @@ def upload(self, *args):
         parser.add_argument("-j", "--json", default=None, action=OnceArgument,
                             help='json file path where the upload information will be written to')
         parser.add_argument("--parallel", action='store_true', default=False,
-                            help='Upload files in parallel using multiple threads '
-                                 'The default number of launched threads is 8')
+                            help='Upload files in parallel using multiple threads. '
+                                 'The default number of launched threads is set to the value of '
+                                 'cpu_count and can be configured using the CONAN_CPU_COUNT '
+                                 'environment variable or defining cpu_count in conan.conf')
 
         args = parser.parse_args(*args)