diff --git a/src/octoprint/templates/dialogs/settings/folders.jinja2 b/src/octoprint/templates/dialogs/settings/folders.jinja2
index f72c04e8..383dc0b0 100644
--- a/src/octoprint/templates/dialogs/settings/folders.jinja2
+++ b/src/octoprint/templates/dialogs/settings/folders.jinja2
@@ -55,4 +55,6 @@
             <input type="text" class="input-mini text-right" data-bind="value: server_diskspace_critical_str">
         </div>
     </div>
+
+    <p>{% trans %}Provide values including size unit. Allowed units are: b, byte, bytes, kb, mb, gb, tb (case insensitive). Example: <code>5MB</code>, <code>500KB</code>{% endtrans %}</p>
 </form>