diff --git a/Marlin/src/gcode/calibrate/M665.cpp b/Marlin/src/gcode/calibrate/M665.cpp
index 3d96facdf099..c7da0fc931f6 100644
--- a/Marlin/src/gcode/calibrate/M665.cpp
+++ b/Marlin/src/gcode/calibrate/M665.cpp
@@ -86,13 +86,13 @@
    *
    * Parameters:
    *
-   *   S[segments-per-second] - Segments-per-second
+   *   S[segments]          - Segments-per-second
    *
    * Without NO_WORKSPACE_OFFSETS:
    *
-   *   P[theta-psi-offset]    - Theta-Psi offset, added to the shoulder (A/X) angle
-   *   T[theta-offset]        - Theta     offset, added to the elbow    (B/Y) angle
-   *   Z[z-offset]            - Z offset, added to Z
+   *   P[theta-psi-offset]  - Theta-Psi offset, added to the shoulder (A/X) angle
+   *   T[theta-offset]      - Theta     offset, added to the elbow    (B/Y) angle
+   *   Z[z-offset]          - Z offset, added to Z
    *
    *   A, P, and X are all aliases for the shoulder angle
    *   B, T, and Y are all aliases for the elbow angle
@@ -152,27 +152,21 @@
    *
    * Parameters:
    *
-   *   S[segments-per-second] - Segments-per-second
-   *   L[left] - draw area minimum X
-   *   R[right] - draw area maximum X
-   *   T[top] - draw area maximum Y
-   *   B[bottom] - draw area minimum Y
-   *   H[max-belt-length] - maximum belt length
+   *   S[segments]  - Segments-per-second
+   *   L[left]      - Work area minimum X
+   *   R[right]     - Work area maximum X
+   *   T[top]       - Work area maximum Y
+   *   B[bottom]    - Work area minimum Y
+   *   H[length]    - Maximum belt length
    */
   void GcodeSuite::M665() {
     if (!parser.seen_any()) return M665_report();
-    if (parser.seenval('S'))
-      segments_per_second = parser.value_float();
-    if (parser.seenval('L'))
-      draw_area_min.x = parser.value_float();
-    if (parser.seenval('R'))
-      draw_area_max.x = parser.value_float();
-    if (parser.seenval('T'))
-      draw_area_max.y = parser.value_float();
-    if (parser.seenval('B'))
-      draw_area_min.y = parser.value_float();
-    if (parser.seenval('H'))
-      polargraph_max_belt_len = parser.value_float();
+    if (parser.seenval('S')) segments_per_second = parser.value_float();
+    if (parser.seenval('L')) draw_area_min.x = parser.value_linear_units();
+    if (parser.seenval('R')) draw_area_max.x = parser.value_linear_units();
+    if (parser.seenval('T')) draw_area_max.y = parser.value_linear_units();
+    if (parser.seenval('B')) draw_area_min.y = parser.value_linear_units();
+    if (parser.seenval('H')) polargraph_max_belt_len = parser.value_linear_units();
     draw_area_size.x = draw_area_max.x - draw_area_min.x;
     draw_area_size.y = draw_area_max.y - draw_area_min.y;
   }
@@ -183,8 +177,8 @@
         PSTR("  M665 S"), LINEAR_UNIT(segments_per_second),
         PSTR(" L"), LINEAR_UNIT(draw_area_min.x),
         PSTR(" R"), LINEAR_UNIT(draw_area_max.x),
-        PSTR(" T"), LINEAR_UNIT(draw_area_max.y),
-        PSTR(" B"), LINEAR_UNIT(draw_area_min.y),
+        SP_T_STR, LINEAR_UNIT(draw_area_max.y),
+        SP_B_STR, LINEAR_UNIT(draw_area_min.y),
         PSTR(" H"), LINEAR_UNIT(polargraph_max_belt_len)
     );
   }