diff --git a/src/gui_qt/_py/basewindow.py b/src/gui_qt/_py/basewindow.py
index 3b24795..d916548 100644
--- a/src/gui_qt/_py/basewindow.py
+++ b/src/gui_qt/_py/basewindow.py
@@ -365,6 +365,9 @@ class Ui_BaseWindow(object):
         self.actionBinning.setObjectName("actionBinning")
         self.actionTNMH = QtWidgets.QAction(BaseWindow)
         self.actionTNMH.setObjectName("actionTNMH")
+        self.actionExclude_region = QtWidgets.QAction(BaseWindow)
+        self.actionExclude_region.setCheckable(True)
+        self.actionExclude_region.setObjectName("actionExclude_region")
         self.menuSave.addAction(self.actionSave)
         self.menuSave.addAction(self.actionExportGraphic)
         self.menuSave.addAction(self.action_save_fit_parameter)
@@ -419,6 +422,7 @@ class Ui_BaseWindow(object):
         self.menuLimits.addAction(self.action_no_range)
         self.menuLimits.addAction(self.action_x_range)
         self.menuLimits.addAction(self.action_custom_range)
+        self.menuLimits.addAction(self.actionExclude_region)
         self.menuFit.addAction(self.action_FitWidget)
         self.menuFit.addSeparator()
         self.menuFit.addAction(self.action_create_fit_function)
@@ -631,6 +635,7 @@ class Ui_BaseWindow(object):
         self.actionTNMH_model.setText(_translate("BaseWindow", "Tg , Hodge, TNMH,,,"))
         self.actionBinning.setText(_translate("BaseWindow", "Binning..."))
         self.actionTNMH.setText(_translate("BaseWindow", "TNMH..."))
+        self.actionExclude_region.setText(_translate("BaseWindow", "Exclude region"))
 from ..data.datawidget.datawidget import DataWidget
 from ..data.integral_widget import IntegralWidget
 from ..data.point_select import PointSelectWidget
diff --git a/src/gui_qt/fit/fit_toolbar.py b/src/gui_qt/fit/fit_toolbar.py
index 4cfa091..283c335 100644
--- a/src/gui_qt/fit/fit_toolbar.py
+++ b/src/gui_qt/fit/fit_toolbar.py
@@ -58,7 +58,8 @@ class FitToolbar(QtWidgets.QToolBar):
 
     @QtCore.pyqtSlot(QtWidgets.QAction)
     def change_limit_type(self, action: QtWidgets.QAction):
-        is_custom = (action.text() == 'Custom')
+        is_custom = (action.text() in ['Custom', 'Exclude region'])
+        print(is_custom)
 
         for w in [self.label, self.label2, self.lineedit, self.lineedit2]:
             w.setEnabled(is_custom)
@@ -93,5 +94,6 @@ class FitToolbar(QtWidgets.QToolBar):
         return {
             'None': 'none',
             'Visible x range': 'x',
-            'Custom': self.region.getRegion(),
+            'Custom': ('in', self.region.getRegion()),
+            'Exclude region': ('out', self.region.getRegion()),
         }[action_text]
diff --git a/src/gui_qt/main/mainwindow.py b/src/gui_qt/main/mainwindow.py
index 80935b6..d91b3ac 100644
--- a/src/gui_qt/main/mainwindow.py
+++ b/src/gui_qt/main/mainwindow.py
@@ -888,7 +888,7 @@ class NMRMainWindow(QtWidgets.QMainWindow, Ui_BaseWindow):
             self.fit_dialog.load(self.management.active_sets)
             for item in self.fit_dialog.preview_lines:
                 self.current_graph_widget.add_external(item)
-            if self.action_custom_range.isChecked():
+            if self.action_custom_range.isChecked() or self.actionExclude_region.isChecked():
                 self.current_graph_widget.add_external(self.fit_toolbar.region)
 
             block_window = True
@@ -904,7 +904,7 @@ class NMRMainWindow(QtWidgets.QMainWindow, Ui_BaseWindow):
         if self.current_graph_widget is None:
             return
 
-        if action == self.action_custom_range and self.fit_dialog.isVisible():
+        if action in [self.action_custom_range, self.actionExclude_region] and self.fit_dialog.isVisible():
             self.current_graph_widget.add_external(self.fit_toolbar.region)
         else:
             self.current_graph_widget.remove_external(self.fit_toolbar.region)
diff --git a/src/gui_qt/main/management.py b/src/gui_qt/main/management.py
index b8758b2..ab07037 100644
--- a/src/gui_qt/main/management.py
+++ b/src/gui_qt/main/management.py
@@ -511,13 +511,16 @@ class UpperManagement(QtCore.QObject):
 
                     _x = data_i.x
 
+                    # options for fit limits 'none', 'x', ('in', custom region), ('out', excluded region)
                     if fit_limits == 'none':
                         inside = slice(None)
                     elif fit_limits == 'x':
                         x_lim, _ = self.graphs[self.current_graph].ranges
                         inside = np.where((_x >= x_lim[0]) & (_x <= x_lim[1]))
+                    elif fit_limits[0] == 'in':
+                        inside = np.where((_x >= fit_limits[1][0]) & (_x <= fit_limits[1][1]))
                     else:
-                        inside = np.where((_x >= fit_limits[0]) & (_x <= fit_limits[1]))
+                        inside = np.where((_x < fit_limits[1][0]) | (_x > fit_limits[1][1]))
 
                     try:
                         if isinstance(we, str):
diff --git a/src/resources/_ui/basewindow.ui b/src/resources/_ui/basewindow.ui
index bf3de79..01987b8 100644
--- a/src/resources/_ui/basewindow.ui
+++ b/src/resources/_ui/basewindow.ui
@@ -247,6 +247,7 @@
      <addaction name="action_no_range"/>
      <addaction name="action_x_range"/>
      <addaction name="action_custom_range"/>
+     <addaction name="actionExclude_region"/>
     </widget>
     <addaction name="action_FitWidget"/>
     <addaction name="separator"/>
@@ -1021,6 +1022,14 @@
     <string>TNMH...</string>
    </property>
   </action>
+  <action name="actionExclude_region">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Exclude region</string>
+   </property>
+  </action>
  </widget>
  <customwidgets>
   <customwidget>