diff --git a/generate_macrodef.py b/generate_macrodef.py
index b86d518..d15f453 100755
--- a/generate_macrodef.py
+++ b/generate_macrodef.py
@@ -253,7 +253,19 @@ def generate_macrodef_h():
     # Define macro buffer_width
     # number of buffer points for mesh-refinement interfaces
     
-    print( "#define buffer_width 6",                     file=file1 )
+    # Calculate ghost_width based on Finite_Diffenence_Method to optimize buffer_width
+    if ( input_data.Finite_Diffenence_Method == "2nd-order" ):
+        gw = 2
+    elif ( input_data.Finite_Diffenence_Method == "4th-order" ):
+        gw = 3
+    elif ( input_data.Finite_Diffenence_Method == "6th-order" ):
+        gw = 4
+    elif ( input_data.Finite_Diffenence_Method == "8th-order" ):
+        gw = 5
+    else:
+        gw = 5 # Default conservative value
+        
+    print( f"#define buffer_width {gw + 1}",      file=file1 )
     print(                                               file=file1 )
 
     # Define macro SC_width as buffer_width