diff --git a/qt-ui/mainwindow.cpp b/qt-ui/mainwindow.cpp
index d3cd951d8..e04d824fb 100644
--- a/qt-ui/mainwindow.cpp
+++ b/qt-ui/mainwindow.cpp
@@ -376,11 +376,17 @@ void MainWindow::readSettings()
 
 	settings.endGroup();
 	settings.beginGroup("Units");
-	GET_UNIT(v, "length", length, units::FEET, units::METERS);
-	GET_UNIT(v, "pressure", pressure, units::PSI, units::BAR);
-	GET_UNIT(v, "volume", volume, units::CUFT, units::LITER);
-	GET_UNIT(v, "temperature", temperature, units::FAHRENHEIT, units::CELSIUS);
-	GET_UNIT(v, "weight", weight, units::LBS, units::KG);
+	if (settings.value("unit_system").toString() == "metric") {
+		prefs.units = SI_units;
+	} else if (settings.value("unit_system").toString() == "imperial") {
+		prefs.units = IMPERIAL_units;
+	} else {
+		GET_UNIT(v, "length", length, units::FEET, units::METERS);
+		GET_UNIT(v, "pressure", pressure, units::PSI, units::BAR);
+		GET_UNIT(v, "volume", volume, units::CUFT, units::LITER);
+		GET_UNIT(v, "temperature", temperature, units::FAHRENHEIT, units::CELSIUS);
+		GET_UNIT(v, "weight", weight, units::LBS, units::KG);
+	}
 	settings.endGroup();
 	settings.beginGroup("DisplayListColumns");
 	GET_BOOL(v, "CYLINDER", prefs.visible_cols.cylinder);
diff --git a/qt-ui/preferences.cpp b/qt-ui/preferences.cpp
index dd484b6e8..551d7965a 100644
--- a/qt-ui/preferences.cpp
+++ b/qt-ui/preferences.cpp
@@ -1,6 +1,7 @@
 #include "preferences.h"
 #include "ui_preferences.h"
 #include <QSettings>
+#include <QDebug>
 
 PreferencesDialog* PreferencesDialog::instance()
 {
@@ -43,6 +44,7 @@ PreferencesDialog::PreferencesDialog(QWidget* parent, Qt::WindowFlags f) : QDial
 	ui->increment_3m->setChecked(B(calcceiling3m, calc_ceiling_3m_incr));
 	ui->all_tissues->setEnabled(ui->calculated_ceiling->isChecked());
 	ui->all_tissues->setChecked(B(calcalltissues, calc_all_tissues));
+	ui->groupBox->setEnabled(ui->personalize->isChecked());
 
 	ui->gflow->setValue((int)(I(gflow, gflow)));
 	ui->gfhigh->setValue((int)(I(gfhigh, gfhigh)));
@@ -121,7 +123,8 @@ void PreferencesDialog::syncSettings()
 
 	// Units
 	s.beginGroup("Units");
-	s.setValue("units_metric", ui->metric->isChecked());
+	QString unitSystem = ui->metric->isChecked() ? "metric" : (ui->imperial->isChecked() ? "imperial" : "personal");
+	s.setValue("unit_system", unitSystem);
 	s.setValue("temperature", ui->fahrenheit->isChecked() ? units::FAHRENHEIT : units::CELSIUS);
 	s.setValue("length", ui->feet->isChecked() ? units::FEET : units::METERS);
 	s.setValue("pressure", ui->psi->isChecked() ? units::PSI : units::BAR);
diff --git a/qt-ui/preferences.ui b/qt-ui/preferences.ui
index 3cef8785a..07a423834 100644
--- a/qt-ui/preferences.ui
+++ b/qt-ui/preferences.ui
@@ -116,7 +116,7 @@
         </sizepolicy>
        </property>
        <property name="currentIndex">
-        <number>2</number>
+        <number>1</number>
        </property>
        <widget class="QWidget" name="page_2">
         <layout class="QVBoxLayout" name="verticalLayout_3">
@@ -224,6 +224,9 @@
              <property name="text">
               <string>Metric</string>
              </property>
+             <attribute name="buttonGroup">
+              <string notr="true">buttonGroup_6</string>
+             </attribute>
             </widget>
            </item>
            <item>
@@ -231,6 +234,19 @@
              <property name="text">
               <string>Imperial</string>
              </property>
+             <attribute name="buttonGroup">
+              <string notr="true">buttonGroup_6</string>
+             </attribute>
+            </widget>
+           </item>
+           <item>
+            <widget class="QRadioButton" name="personalize">
+             <property name="text">
+              <string>Personalize</string>
+             </property>
+             <attribute name="buttonGroup">
+              <string notr="true">buttonGroup_6</string>
+             </attribute>
             </widget>
            </item>
           </layout>
@@ -238,10 +254,10 @@
          <item>
           <widget class="QGroupBox" name="groupBox">
            <property name="title">
-            <string>Personalize</string>
+            <string/>
            </property>
            <property name="checkable">
-            <bool>true</bool>
+            <bool>false</bool>
            </property>
            <property name="checked">
             <bool>false</bool>
@@ -948,6 +964,22 @@
     </hint>
    </hints>
   </connection>
+  <connection>
+   <sender>personalize</sender>
+   <signal>toggled(bool)</signal>
+   <receiver>groupBox</receiver>
+   <slot>setEnabled(bool)</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>613</x>
+     <y>41</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>634</x>
+     <y>72</y>
+    </hint>
+   </hints>
+  </connection>
  </connections>
  <buttongroups>
   <buttongroup name="buttonGroup_2"/>
@@ -955,5 +987,6 @@
   <buttongroup name="buttonGroup_4"/>
   <buttongroup name="buttonGroup_5"/>
   <buttongroup name="buttonGroup"/>
+  <buttongroup name="buttonGroup_6"/>
  </buttongroups>
 </ui>