diff --git a/Marlin/Marlin.h b/Marlin/Marlin.h
index bdcc9f149..0c3a3ac6d 100644
--- a/Marlin/Marlin.h
+++ b/Marlin/Marlin.h
@@ -269,7 +269,7 @@ extern float homing_feedrate[];
 extern bool axis_relative_modes[];
 extern int feedrate_multiplier;
 extern bool volumetric_enabled;
-extern int extruder_multiply[EXTRUDERS]; // sets extrude multiply factor (in percent) for each extruder individually
+extern int extruder_multiplier[EXTRUDERS]; // sets extrude multiply factor (in percent) for each extruder individually
 extern float filament_size[EXTRUDERS]; // cross-sectional area of filament (in millimeters), typically around 1.75 or 2.85, 0 disables the volumetric calculations for the extruder.
 extern float volumetric_multiplier[EXTRUDERS]; // reciprocal of cross-sectional area of filament (in square millimeters), stored this way to reduce computational burden in planner
 extern float current_position[NUM_AXIS];
diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index a31045843..99ed103dd 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -251,7 +251,7 @@ float homing_feedrate[] = HOMING_FEEDRATE;
 bool axis_relative_modes[] = AXIS_RELATIVE_MODES;
 int feedrate_multiplier = 100; //100->1 200->2
 int saved_feedrate_multiplier;
-int extruder_multiply[EXTRUDERS] = ARRAY_BY_EXTRUDERS(100, 100, 100, 100);
+int extruder_multiplier[EXTRUDERS] = ARRAY_BY_EXTRUDERS(100, 100, 100, 100);
 bool volumetric_enabled = false;
 float filament_size[EXTRUDERS] = ARRAY_BY_EXTRUDERS(DEFAULT_NOMINAL_FILAMENT_DIA, DEFAULT_NOMINAL_FILAMENT_DIA, DEFAULT_NOMINAL_FILAMENT_DIA, DEFAULT_NOMINAL_FILAMENT_DIA);
 float volumetric_multiplier[EXTRUDERS] = ARRAY_BY_EXTRUDERS(1.0, 1.0, 1.0, 1.0);
@@ -4187,10 +4187,10 @@ inline void gcode_M221() {
     int sval = code_value();
     if (code_seen('T')) {
       if (setTargetedHotend(221)) return;
-      extruder_multiply[target_extruder] = sval;
+      extruder_multiplier[target_extruder] = sval;
     }
     else {
-      extruder_multiply[active_extruder] = sval;
+      extruder_multiplier[active_extruder] = sval;
     }
   }
 }
@@ -4637,7 +4637,7 @@ inline void gcode_M400() { st_synchronize(); }
     //SERIAL_PROTOCOLPGM("Filament dia (measured mm):");
     //SERIAL_PROTOCOL(filament_width_meas);
     //SERIAL_PROTOCOLPGM("Extrusion ratio(%):");
-    //SERIAL_PROTOCOL(extruder_multiply[active_extruder]);
+    //SERIAL_PROTOCOL(extruder_multiplier[active_extruder]);
   }
 
   /**
diff --git a/Marlin/planner.cpp b/Marlin/planner.cpp
index 02bde4877..06b9bc5e2 100644
--- a/Marlin/planner.cpp
+++ b/Marlin/planner.cpp
@@ -540,7 +540,7 @@ float junction_deviation = 0.1;
   block->steps[Z_AXIS] = labs(dz);
   block->steps[E_AXIS] = labs(de);
   block->steps[E_AXIS] *= volumetric_multiplier[extruder];
-  block->steps[E_AXIS] *= extruder_multiply[extruder];
+  block->steps[E_AXIS] *= extruder_multiplier[extruder];
   block->steps[E_AXIS] /= 100;
   block->step_event_count = max(block->steps[X_AXIS], max(block->steps[Y_AXIS], max(block->steps[Z_AXIS], block->steps[E_AXIS])));
 
@@ -674,7 +674,7 @@ float junction_deviation = 0.1;
     delta_mm[Y_AXIS] = dy / axis_steps_per_unit[Y_AXIS];
   #endif
   delta_mm[Z_AXIS] = dz / axis_steps_per_unit[Z_AXIS];
-  delta_mm[E_AXIS] = (de / axis_steps_per_unit[E_AXIS]) * volumetric_multiplier[extruder] * extruder_multiply[extruder] / 100.0;
+  delta_mm[E_AXIS] = (de / axis_steps_per_unit[E_AXIS]) * volumetric_multiplier[extruder] * extruder_multiplier[extruder] / 100.0;
 
   if (block->steps[X_AXIS] <= dropsegments && block->steps[Y_AXIS] <= dropsegments && block->steps[Z_AXIS] <= dropsegments) {
     block->millimeters = fabs(delta_mm[E_AXIS]);
diff --git a/Marlin/ultralcd.cpp b/Marlin/ultralcd.cpp
index 31bc809ec..d3e44719d 100644
--- a/Marlin/ultralcd.cpp
+++ b/Marlin/ultralcd.cpp
@@ -488,16 +488,16 @@ static void lcd_tune_menu() {
     MENU_MULTIPLIER_ITEM_EDIT(int3, MSG_BED, &target_temperature_bed, 0, BED_MAXTEMP - 15);
   #endif
   MENU_MULTIPLIER_ITEM_EDIT(int3, MSG_FAN_SPEED, &fanSpeed, 0, 255);
-  MENU_ITEM_EDIT(int3, MSG_FLOW, &extruder_multiply[active_extruder], 10, 999);
-  MENU_ITEM_EDIT(int3, MSG_FLOW MSG_N0, &extruder_multiply[0], 10, 999);
+  MENU_ITEM_EDIT(int3, MSG_FLOW, &extruder_multiplier[active_extruder], 10, 999);
+  MENU_ITEM_EDIT(int3, MSG_FLOW MSG_N0, &extruder_multiplier[0], 10, 999);
   #if TEMP_SENSOR_1 != 0
-    MENU_ITEM_EDIT(int3, MSG_FLOW MSG_N1, &extruder_multiply[1], 10, 999);
+    MENU_ITEM_EDIT(int3, MSG_FLOW MSG_N1, &extruder_multiplier[1], 10, 999);
   #endif
   #if TEMP_SENSOR_2 != 0
-    MENU_ITEM_EDIT(int3, MSG_FLOW MSG_N2, &extruder_multiply[2], 10, 999);
+    MENU_ITEM_EDIT(int3, MSG_FLOW MSG_N2, &extruder_multiplier[2], 10, 999);
   #endif
   #if TEMP_SENSOR_3 != 0
-    MENU_ITEM_EDIT(int3, MSG_FLOW MSG_N3, &extruder_multiply[3], 10, 999);
+    MENU_ITEM_EDIT(int3, MSG_FLOW MSG_N3, &extruder_multiplier[3], 10, 999);
   #endif
 
   #ifdef BABYSTEPPING