diff --git a/CMakeLists.txt b/CMakeLists.txt
index 75ca0e9..7c2aafc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -123,6 +123,14 @@ if(BUILD_TESTING)
     COMMAND tmux-mem-cpu-load 2 8
     )
 
+  add_test(NAME memory_mode_free_memory
+    COMMAND tmux-mem-cpu-load -m 1
+    )
+
+  add_test(NAME memory_mode_used_percentage
+    COMMAND tmux-mem-cpu-load -m 2
+    )
+
   set_tests_properties(usage
     invalid_status_interval
     invalid_graph_lines
diff --git a/common/main.cc b/common/main.cc
index 8eedfd1..d111ee0 100644
--- a/common/main.cc
+++ b/common/main.cc
@@ -93,7 +93,7 @@ int main( int argc, char** argv )
   unsigned cpu_usage_delay = 990000;
   short graph_lines = 10; // max 32767 should be enough
   bool use_colors = false;
-  int mem_mode = 0;
+  int mem_mode = MEMORY_MODE_DEFAULT;
 
   static struct option long_options[] =
   {
diff --git a/common/memory.h b/common/memory.h
index 814d81e..cefbf82 100644
--- a/common/memory.h
+++ b/common/memory.h
@@ -16,6 +16,13 @@
  * limitations under the License.
  */
 
+enum
+{
+  MEMORY_MODE_DEFAULT,
+  MEMORY_MODE_FREE_MEMORY,
+  MEMORY_MODE_USAGE_PERCENTAGE
+};
+
 #ifndef MEMORY_H_
 #define MEMORY_H_
 
diff --git a/osx/memory.cc b/osx/memory.cc
index 35c47d6..15498d6 100644
--- a/osx/memory.cc
+++ b/osx/memory.cc
@@ -33,6 +33,8 @@ std::string mem_string( bool use_colors, int mode )
   u_int64_t total_mem;
   float used_mem;
   float percentage_mem;
+  float free_mem;
+  float free_mem_in_gigabytes; // used to check if free mem < 1 GB
   //u_int64_t unused_mem;
 
   vm_size_t page_size;
@@ -61,25 +63,36 @@ std::string mem_string( bool use_colors, int mode )
     oss << mem_lut[( 100 * static_cast<u_int64_t>(used_mem) ) / total_mem];
   }
 
-
-  percentage_mem = static_cast<float>(used_mem) / static_cast<float>(total_mem) * 100.0;
-
+  // Change the percision for floats, for a pretty output
   oss.precision( 2 );
   oss.setf( std::ios::fixed | std::ios::right );
 
-  if( mode == 0 ) {
-    oss << convert_unit( used_mem, MEGABYTES ) << '/' 
-      << convert_unit( total_mem, MEGABYTES ) << "MB";
-  } else if ( mode == 1 ) {
-    float free_mem = total_mem - used_mem;
+  switch( mode )
+  {
+    case MEMORY_MODE_FREE_MEMORY: // Show free memory in MB or GB
+      free_mem = total_mem - used_mem;
+      free_mem_in_gigabytes = convert_unit( free_mem, GIGABYTES  );
 
-    if( free_mem < 1 ) {
-      oss << convert_unit( free_mem, MEGABYTES ) << "MB";
-    } else {
-      oss << convert_unit( free_mem, GIGABYTES ) << "GB";
-    }
-  } else {
-    oss << percentage_mem << '%';
+      // if free memory is less than 1 GB, use MB instead
+      if(  free_mem_in_gigabytes < 1 )
+      {
+        oss << convert_unit( free_mem, MEGABYTES ) << "MB";
+      } 
+      else 
+      {
+        oss << free_mem_in_gigabytes << "GB";
+      }
+      break;
+    case MEMORY_MODE_USAGE_PERCENTAGE:
+      // Calculate the percentage of used memory
+      percentage_mem = used_mem / 
+        static_cast<float>( total_mem ) * 100.0;
+
+      oss << percentage_mem << '%';
+      break;
+    default: // Default mode, just show the used/total memory in MB 
+      oss << convert_unit( used_mem, MEGABYTES ) << '/' 
+        << convert_unit( total_mem, MEGABYTES ) << "MB"; 
   }
 
   if( use_colors )