diff --git a/Marlin/src/core/types.h b/Marlin/src/core/types.h
index 4c7ebc884f..9581558604 100644
--- a/Marlin/src/core/types.h
+++ b/Marlin/src/core/types.h
@@ -276,6 +276,9 @@ typedef float celsius_float_t;
 typedef const_float_t const_feedRate_t;
 typedef const_float_t const_celsius_float_t;
 
+// Type large enough to count leveling grid points
+typedef IF<TERN0(ABL_USES_GRID, (GRID_MAX_POINTS > 255)), uint16_t, uint8_t>::type grid_count_t;
+
 // Conversion macros
 #define MMM_TO_MMS(MM_M) feedRate_t(static_cast<float>(MM_M) / 60.0f)
 #define MMS_TO_MMM(MM_S) (static_cast<float>(MM_S) * 60.0f)
diff --git a/Marlin/src/feature/bedlevel/ubl/ubl.h b/Marlin/src/feature/bedlevel/ubl/ubl.h
index 05a937c985..785cb5d883 100644
--- a/Marlin/src/feature/bedlevel/ubl/ubl.h
+++ b/Marlin/src/feature/bedlevel/ubl/ubl.h
@@ -48,8 +48,8 @@ struct mesh_index_pair;
 typedef struct {
   bool      C_seen;
   int8_t    KLS_storage_slot;
-  uint8_t   R_repetition,
-            V_verbosity,
+  grid_count_t R_repetition;
+  uint8_t   V_verbosity,
             P_phase,
             T_map_type;
   float     B_shim_thickness,
diff --git a/Marlin/src/feature/bedlevel/ubl/ubl_G29.cpp b/Marlin/src/feature/bedlevel/ubl/ubl_G29.cpp
index 2fbd3bfbeb..ecbf76ec6e 100644
--- a/Marlin/src/feature/bedlevel/ubl/ubl_G29.cpp
+++ b/Marlin/src/feature/bedlevel/ubl/ubl_G29.cpp
@@ -351,7 +351,7 @@ void unified_bed_leveling::G29() {
 
   // Invalidate one or more nearby mesh points, possibly all.
   if (parser.seen('I')) {
-    uint8_t count = parser.has_value() ? parser.value_byte() : 1;
+    grid_count_t count = parser.has_value() ? parser.value_ushort() : 1;
     bool invalidate_all = count >= GRID_MAX_POINTS;
     if (!invalidate_all) {
       while (count--) {
@@ -760,14 +760,14 @@ void unified_bed_leveling::shift_mesh_height() {
     TERN_(DWIN_LCD_PROUI, DWIN_LevelingStart());
 
     save_ubl_active_state_and_disable();  // No bed level correction so only raw data is obtained
-    uint8_t count = GRID_MAX_POINTS;
+    grid_count_t count = GRID_MAX_POINTS;
 
     mesh_index_pair best;
     TERN_(EXTENSIBLE_UI, ExtUI::onMeshUpdate(best.pos, ExtUI::G29_START));
     do {
       if (do_ubl_mesh_map) display_map(param.T_map_type);
 
-      const uint8_t point_num = (GRID_MAX_POINTS - count) + 1;
+      const grid_count_t point_num = (GRID_MAX_POINTS - count) + 1;
       SERIAL_ECHOLNPGM("Probing mesh point ", point_num, "/", GRID_MAX_POINTS, ".");
       TERN_(HAS_STATUS_MESSAGE, ui.status_printf(0, F(S_FMT " %i/%i"), GET_TEXT(MSG_PROBING_POINT), point_num, int(GRID_MAX_POINTS)));
 
@@ -1135,7 +1135,7 @@ bool unified_bed_leveling::G29_parse_parameters() {
   param.R_repetition = 0;
 
   if (parser.seen('R')) {
-    param.R_repetition = parser.has_value() ? parser.value_byte() : GRID_MAX_POINTS;
+    param.R_repetition = parser.has_value() ? parser.value_ushort() : GRID_MAX_POINTS;
     NOMORE(param.R_repetition, GRID_MAX_POINTS);
     if (param.R_repetition < 1) {
       SERIAL_ECHOLNPGM("?(R)epetition count invalid (1+).\n");
diff --git a/Marlin/src/gcode/bedlevel/G26.cpp b/Marlin/src/gcode/bedlevel/G26.cpp
index fe20423b8d..1b55bdb428 100644
--- a/Marlin/src/gcode/bedlevel/G26.cpp
+++ b/Marlin/src/gcode/bedlevel/G26.cpp
@@ -628,7 +628,7 @@ void GcodeSuite::G26() {
   }
 
   // Get repeat from 'R', otherwise do one full circuit
-  int16_t g26_repeats;
+  grid_count_t g26_repeats;
   #if HAS_MARLINUI_MENU
     g26_repeats = parser.intval('R', GRID_MAX_POINTS + 1);
   #else
diff --git a/Marlin/src/gcode/bedlevel/abl/G29.cpp b/Marlin/src/gcode/bedlevel/abl/G29.cpp
index dd325284af..1fe4a31bee 100644
--- a/Marlin/src/gcode/bedlevel/abl/G29.cpp
+++ b/Marlin/src/gcode/bedlevel/abl/G29.cpp
@@ -102,11 +102,11 @@ public:
   #endif
 
   #if ENABLED(AUTO_BED_LEVELING_LINEAR)
-    int abl_points;
+    grid_count_t abl_points;
   #elif ENABLED(AUTO_BED_LEVELING_3POINT)
-    static constexpr int abl_points = 3;
+    static constexpr grid_count_t abl_points = 3;
   #elif ABL_USES_GRID
-    static constexpr int abl_points = GRID_MAX_POINTS;
+    static constexpr grid_count_t abl_points = GRID_MAX_POINTS;
   #endif
 
   #if ABL_USES_GRID
@@ -132,8 +132,8 @@ public:
 
     #if ENABLED(AUTO_BED_LEVELING_LINEAR)
       int indexIntoAB[GRID_MAX_POINTS_X][GRID_MAX_POINTS_Y];
-      float eqnAMatrix[(GRID_MAX_POINTS) * 3], // "A" matrix of the linear system of equations
-            eqnBVector[GRID_MAX_POINTS],       // "B" vector of Z points
+      float eqnAMatrix[GRID_MAX_POINTS * 3],  // "A" matrix of the linear system of equations
+            eqnBVector[GRID_MAX_POINTS],      // "B" vector of Z points
             mean;
     #endif
   #endif
@@ -141,7 +141,7 @@ public:
 
 #if ABL_USES_GRID && EITHER(AUTO_BED_LEVELING_3POINT, AUTO_BED_LEVELING_BILINEAR)
   constexpr xy_uint8_t G29_State::grid_points;
-  constexpr int G29_State::abl_points;
+  constexpr grid_count_t G29_State::abl_points;
 #endif
 
 /**
@@ -677,7 +677,7 @@ G29_TYPE GcodeSuite::G29() {
         zig ^= true; // zag
 
         // An index to print current state
-        uint8_t pt_index = (PR_OUTER_VAR) * (PR_INNER_SIZE) + 1;
+        grid_count_t pt_index = (PR_OUTER_VAR) * (PR_INNER_SIZE) + 1;
 
         // Inner loop is Y with PROBE_Y_FIRST enabled
         // Inner loop is X with PROBE_Y_FIRST disabled
diff --git a/Marlin/src/gcode/bedlevel/mbl/G29.cpp b/Marlin/src/gcode/bedlevel/mbl/G29.cpp
index 9f902141fb..4bc9ba777a 100644
--- a/Marlin/src/gcode/bedlevel/mbl/G29.cpp
+++ b/Marlin/src/gcode/bedlevel/mbl/G29.cpp
@@ -173,7 +173,7 @@ void GcodeSuite::G29() {
         SET_SOFT_ENDSTOP_LOOSE(false);
       }
       // If there's another point to sample, move there with optional lift.
-      if (mbl_probe_index < (GRID_MAX_POINTS)) {
+      if (mbl_probe_index < GRID_MAX_POINTS) {
         // Disable software endstops to allow manual adjustment
         // If G29 is left hanging without completion they won't be re-enabled!
         SET_SOFT_ENDSTOP_LOOSE(true);
diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
index 67d11d93e0..f77bf7afeb 100644
--- a/Marlin/src/inc/SanityCheck.h
+++ b/Marlin/src/inc/SanityCheck.h
@@ -1498,8 +1498,8 @@ static_assert(COUNT(arm) == LOGICAL_AXES, "AXIS_RELATIVE_MODES must contain " _L
     #error "AUTO_BED_LEVELING_UBL does not yet support POLAR printers."
   #elif DISABLED(EEPROM_SETTINGS)
     #error "AUTO_BED_LEVELING_UBL requires EEPROM_SETTINGS."
-  #elif !WITHIN(GRID_MAX_POINTS_X, 3, 15) || !WITHIN(GRID_MAX_POINTS_Y, 3, 15)
-    #error "GRID_MAX_POINTS_[XY] must be a whole number between 3 and 15."
+  #elif !WITHIN(GRID_MAX_POINTS_X, 3, 255) || !WITHIN(GRID_MAX_POINTS_Y, 3, 255)
+    #error "GRID_MAX_POINTS_[XY] must be between 3 and 255."
   #endif
 
 #elif HAS_ABL_NOT_UBL
@@ -1513,6 +1513,8 @@ static_assert(COUNT(arm) == LOGICAL_AXES, "AXIS_RELATIVE_MODES must contain " _L
    */
   #if IS_SCARA && DISABLED(AUTO_BED_LEVELING_BILINEAR)
     #error "SCARA machines can only use the AUTO_BED_LEVELING_BILINEAR leveling option."
+  #elif ABL_USES_GRID && !(WITHIN(GRID_MAX_POINTS_X, 3, 255) && WITHIN(GRID_MAX_POINTS_Y, 3, 255))
+    #error "GRID_MAX_POINTS_[XY] must be between 3 and 255."
   #endif
 
 #elif ENABLED(MESH_BED_LEVELING)
diff --git a/Marlin/src/lcd/e3v2/jyersui/dwin.cpp b/Marlin/src/lcd/e3v2/jyersui/dwin.cpp
index e7f15792f3..f430f6d1a9 100644
--- a/Marlin/src/lcd/e3v2/jyersui/dwin.cpp
+++ b/Marlin/src/lcd/e3v2/jyersui/dwin.cpp
@@ -202,7 +202,7 @@ bool livemove = false;
 bool liveadjust = false;
 uint8_t preheatmode = 0;
 float zoffsetvalue = 0;
-uint8_t gridpoint;
+grid_count_t gridpoint;
 float corner_avg;
 float corner_pos;
 
diff --git a/Marlin/src/lcd/extui/anycubic_vyper/dgus_tft.cpp b/Marlin/src/lcd/extui/anycubic_vyper/dgus_tft.cpp
index 387557f2af..e846d65a1f 100644
--- a/Marlin/src/lcd/extui/anycubic_vyper/dgus_tft.cpp
+++ b/Marlin/src/lcd/extui/anycubic_vyper/dgus_tft.cpp
@@ -549,7 +549,7 @@ namespace Anycubic {
     bool msg_matched = false;
 
     #if HAS_LEVELING
-      static uint8_t probe_cnt = 0;
+      static grid_count_t probe_cnt = 0;
     #endif
 
     // The only way to get printer status is to parse messages
@@ -564,7 +564,7 @@ namespace Anycubic {
           // If probing completes ok save the mesh and park
           // Ignore the custom machine name
           if (strcmp_P(msg + strlen(MACHINE_NAME), MARLIN_msg_ready) == 0) {
-            if (probe_cnt == GRID_MAX_POINTS_X * GRID_MAX_POINTS_Y) {
+            if (probe_cnt == GRID_MAX_POINTS) {
               probe_cnt = 0;
               injectCommands(F("M500"));    // G27 park nozzle
               //ChangePageOfTFT(PAGE_PreLEVEL);
diff --git a/Marlin/src/lcd/extui/dgus/mks/DGUSScreenHandler.cpp b/Marlin/src/lcd/extui/dgus/mks/DGUSScreenHandler.cpp
index c06971fb10..f882ba33d0 100644
--- a/Marlin/src/lcd/extui/dgus/mks/DGUSScreenHandler.cpp
+++ b/Marlin/src/lcd/extui/dgus/mks/DGUSScreenHandler.cpp
@@ -415,7 +415,7 @@ void DGUSScreenHandlerMKS::LanguageChange(DGUS_VP_Variable &var, void *val_ptr)
 }
 
 #if ENABLED(MESH_BED_LEVELING)
-  uint8_t mesh_point_count = GRID_MAX_POINTS;
+  grid_count_t mesh_point_count = GRID_MAX_POINTS;
 #endif
 
 void DGUSScreenHandlerMKS::Level_Ctrl(DGUS_VP_Variable &var, void *val_ptr) {
diff --git a/Marlin/src/lcd/extui/ftdi_eve_touch_ui/generic/bed_mesh_view_screen.h b/Marlin/src/lcd/extui/ftdi_eve_touch_ui/generic/bed_mesh_view_screen.h
index b9791fff7a..3ec8e06adf 100644
--- a/Marlin/src/lcd/extui/ftdi_eve_touch_ui/generic/bed_mesh_view_screen.h
+++ b/Marlin/src/lcd/extui/ftdi_eve_touch_ui/generic/bed_mesh_view_screen.h
@@ -26,7 +26,7 @@
 
 struct BedMeshViewScreenData {
   FSTR_P message;
-  uint8_t count;
+  grid_count_t count;
   xy_uint8_t highlight;
 };
 
diff --git a/Marlin/src/lcd/menu/menu_bed_leveling.cpp b/Marlin/src/lcd/menu/menu_bed_leveling.cpp
index 3d6af0012d..dcf77cb3eb 100644
--- a/Marlin/src/lcd/menu/menu_bed_leveling.cpp
+++ b/Marlin/src/lcd/menu/menu_bed_leveling.cpp
@@ -53,7 +53,7 @@
   //
 
   // LCD probed points are from defaults
-  constexpr uint8_t total_probe_points = TERN(AUTO_BED_LEVELING_3POINT, 3, GRID_MAX_POINTS);
+  constexpr grid_count_t total_probe_points = TERN(AUTO_BED_LEVELING_3POINT, 3, GRID_MAX_POINTS);
 
   //
   // Bed leveling is done. Wait for G29 to complete.
diff --git a/Marlin/src/module/settings.cpp b/Marlin/src/module/settings.cpp
index b6e605e853..58e00b7fb0 100644
--- a/Marlin/src/module/settings.cpp
+++ b/Marlin/src/module/settings.cpp
@@ -901,7 +901,7 @@ void MarlinSettings::postprocess() {
     {
       #if ENABLED(MESH_BED_LEVELING)
         static_assert(
-          sizeof(bedlevel.z_values) == (GRID_MAX_POINTS) * sizeof(bedlevel.z_values[0][0]),
+          sizeof(bedlevel.z_values) == GRID_MAX_POINTS * sizeof(bedlevel.z_values[0][0]),
           "MBL Z array is the wrong size."
         );
       #else
@@ -955,7 +955,7 @@ void MarlinSettings::postprocess() {
     {
       #if ENABLED(AUTO_BED_LEVELING_BILINEAR)
         static_assert(
-          sizeof(bedlevel.z_values) == (GRID_MAX_POINTS) * sizeof(bedlevel.z_values[0][0]),
+          sizeof(bedlevel.z_values) == GRID_MAX_POINTS * sizeof(bedlevel.z_values[0][0]),
           "Bilinear Z array is the wrong size."
         );
       #endif