diff --git a/src/gui_qt/_py/fitresult.py b/src/gui_qt/_py/fitresult.py
index 54becc9..0f73b79 100644
--- a/src/gui_qt/_py/fitresult.py
+++ b/src/gui_qt/_py/fitresult.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Form implementation generated from reading ui file 'resources/_ui/fitresult.ui'
+# Form implementation generated from reading ui file 'src/resources/_ui/fitresult.ui'
 #
 # Created by: PyQt5 UI code generator 5.15.10
 #
@@ -157,67 +157,91 @@ class Ui_Dialog(object):
         self.gridLayout_2.setContentsMargins(3, 3, 3, 3)
         self.gridLayout_2.setSpacing(3)
         self.gridLayout_2.setObjectName("gridLayout_2")
-        self.extrapolate_box = QtWidgets.QCheckBox(self.groupBox)
-        self.extrapolate_box.setObjectName("extrapolate_box")
-        self.gridLayout_2.addWidget(self.extrapolate_box, 1, 0, 1, 1)
-        self.parameter_checkbox = QtWidgets.QCheckBox(self.groupBox)
-        self.parameter_checkbox.setObjectName("parameter_checkbox")
-        self.gridLayout_2.addWidget(self.parameter_checkbox, 0, 5, 1, 1)
         self.graph_comboBox = QtWidgets.QComboBox(self.groupBox)
         self.graph_comboBox.setEnabled(False)
-        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Fixed)
+        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.MinimumExpanding, QtWidgets.QSizePolicy.Fixed)
         sizePolicy.setHorizontalStretch(0)
         sizePolicy.setVerticalStretch(0)
         sizePolicy.setHeightForWidth(self.graph_comboBox.sizePolicy().hasHeightForWidth())
         self.graph_comboBox.setSizePolicy(sizePolicy)
         self.graph_comboBox.setObjectName("graph_comboBox")
-        self.gridLayout_2.addWidget(self.graph_comboBox, 1, 6, 1, 1)
-        self.graph_checkBox = QtWidgets.QCheckBox(self.groupBox)
-        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Maximum, QtWidgets.QSizePolicy.Fixed)
-        sizePolicy.setHorizontalStretch(0)
-        sizePolicy.setVerticalStretch(0)
-        sizePolicy.setHeightForWidth(self.graph_checkBox.sizePolicy().hasHeightForWidth())
-        self.graph_checkBox.setSizePolicy(sizePolicy)
-        self.graph_checkBox.setChecked(True)
-        self.graph_checkBox.setObjectName("graph_checkBox")
-        self.gridLayout_2.addWidget(self.graph_checkBox, 1, 5, 1, 1)
+        self.gridLayout_2.addWidget(self.graph_comboBox, 1, 7, 1, 1)
         self.minx_line = QtWidgets.QLineEdit(self.groupBox)
         self.minx_line.setEnabled(False)
-        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Fixed)
+        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Maximum, QtWidgets.QSizePolicy.Fixed)
         sizePolicy.setHorizontalStretch(0)
         sizePolicy.setVerticalStretch(0)
         sizePolicy.setHeightForWidth(self.minx_line.sizePolicy().hasHeightForWidth())
         self.minx_line.setSizePolicy(sizePolicy)
         self.minx_line.setObjectName("minx_line")
         self.gridLayout_2.addWidget(self.minx_line, 1, 1, 1, 1)
-        self.line_2 = QtWidgets.QFrame(self.groupBox)
-        self.line_2.setFrameShape(QtWidgets.QFrame.VLine)
-        self.line_2.setFrameShadow(QtWidgets.QFrame.Sunken)
-        self.line_2.setObjectName("line_2")
-        self.gridLayout_2.addWidget(self.line_2, 0, 4, 2, 1)
+        self.extrapolate_box = QtWidgets.QCheckBox(self.groupBox)
+        self.extrapolate_box.setObjectName("extrapolate_box")
+        self.gridLayout_2.addWidget(self.extrapolate_box, 1, 0, 1, 1)
+        self.numx_line = QtWidgets.QLineEdit(self.groupBox)
+        self.numx_line.setEnabled(False)
+        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.numx_line.sizePolicy().hasHeightForWidth())
+        self.numx_line.setSizePolicy(sizePolicy)
+        self.numx_line.setObjectName("numx_line")
+        self.gridLayout_2.addWidget(self.numx_line, 1, 3, 1, 1)
+        self.graph_checkBox = QtWidgets.QCheckBox(self.groupBox)
+        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.MinimumExpanding, QtWidgets.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.graph_checkBox.sizePolicy().hasHeightForWidth())
+        self.graph_checkBox.setSizePolicy(sizePolicy)
+        self.graph_checkBox.setChecked(True)
+        self.graph_checkBox.setObjectName("graph_checkBox")
+        self.gridLayout_2.addWidget(self.graph_checkBox, 1, 6, 1, 1)
         self.maxx_line = QtWidgets.QLineEdit(self.groupBox)
         self.maxx_line.setEnabled(False)
-        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Fixed)
+        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Maximum, QtWidgets.QSizePolicy.Fixed)
         sizePolicy.setHorizontalStretch(0)
         sizePolicy.setVerticalStretch(0)
         sizePolicy.setHeightForWidth(self.maxx_line.sizePolicy().hasHeightForWidth())
         self.maxx_line.setSizePolicy(sizePolicy)
         self.maxx_line.setObjectName("maxx_line")
         self.gridLayout_2.addWidget(self.maxx_line, 1, 2, 1, 1)
-        self.numx_line = QtWidgets.QLineEdit(self.groupBox)
-        self.numx_line.setEnabled(False)
-        self.numx_line.setObjectName("numx_line")
-        self.gridLayout_2.addWidget(self.numx_line, 1, 3, 1, 1)
+        self.line_2 = QtWidgets.QFrame(self.groupBox)
+        self.line_2.setFrameShape(QtWidgets.QFrame.VLine)
+        self.line_2.setFrameShadow(QtWidgets.QFrame.Sunken)
+        self.line_2.setObjectName("line_2")
+        self.gridLayout_2.addWidget(self.line_2, 0, 5, 2, 1)
+        self.newx_log_checkbox = QtWidgets.QCheckBox(self.groupBox)
+        self.newx_log_checkbox.setEnabled(False)
+        self.newx_log_checkbox.setObjectName("newx_log_checkbox")
+        self.gridLayout_2.addWidget(self.newx_log_checkbox, 1, 4, 1, 1)
         self.horizontalLayout = QtWidgets.QHBoxLayout()
         self.horizontalLayout.setObjectName("horizontalLayout")
         self.curve_checkbox = QtWidgets.QCheckBox(self.groupBox)
+        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.curve_checkbox.sizePolicy().hasHeightForWidth())
+        self.curve_checkbox.setSizePolicy(sizePolicy)
         self.curve_checkbox.setChecked(True)
         self.curve_checkbox.setObjectName("curve_checkbox")
         self.horizontalLayout.addWidget(self.curve_checkbox)
         self.partial_checkBox = QtWidgets.QCheckBox(self.groupBox)
+        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.partial_checkBox.sizePolicy().hasHeightForWidth())
+        self.partial_checkBox.setSizePolicy(sizePolicy)
         self.partial_checkBox.setObjectName("partial_checkBox")
         self.horizontalLayout.addWidget(self.partial_checkBox)
-        self.gridLayout_2.addLayout(self.horizontalLayout, 0, 0, 1, 4)
+        self.gridLayout_2.addLayout(self.horizontalLayout, 0, 0, 1, 5)
+        self.parameter_checkbox = QtWidgets.QCheckBox(self.groupBox)
+        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.MinimumExpanding, QtWidgets.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.parameter_checkbox.sizePolicy().hasHeightForWidth())
+        self.parameter_checkbox.setSizePolicy(sizePolicy)
+        self.parameter_checkbox.setObjectName("parameter_checkbox")
+        self.gridLayout_2.addWidget(self.parameter_checkbox, 0, 6, 1, 2)
         self.gridLayout.addWidget(self.groupBox, 7, 0, 1, 2)
         self.buttonBox = QtWidgets.QDialogButtonBox(Dialog)
         self.buttonBox.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel|QtWidgets.QDialogButtonBox.Ok|QtWidgets.QDialogButtonBox.Retry)
@@ -253,16 +277,17 @@ class Ui_Dialog(object):
         self.del_prev_checkBox.setText(_translate("Dialog", "Delete previous fits of this set"))
         self.reject_fit_checkBox.setText(_translate("Dialog", "Reject this fit"))
         self.groupBox.setTitle(_translate("Dialog", "Output"))
-        self.extrapolate_box.setToolTip(_translate("Dialog", "Extrapolates only main function"))
-        self.extrapolate_box.setText(_translate("Dialog", "Extrapolate curves"))
-        self.parameter_checkbox.setText(_translate("Dialog", "Plot parameter"))
-        self.graph_checkBox.setText(_translate("Dialog", "New graph for parameter"))
         self.minx_line.setToolTip(_translate("Dialog", "Leave empty to start at lowest point"))
         self.minx_line.setPlaceholderText(_translate("Dialog", "min x"))
+        self.extrapolate_box.setToolTip(_translate("Dialog", "Extrapolates only main function"))
+        self.extrapolate_box.setText(_translate("Dialog", "Extrapolate curves"))
+        self.numx_line.setPlaceholderText(_translate("Dialog", "# pts"))
+        self.graph_checkBox.setText(_translate("Dialog", "New graph for parameter"))
         self.maxx_line.setToolTip(_translate("Dialog", "Leave empty to start at highest point"))
         self.maxx_line.setPlaceholderText(_translate("Dialog", "max x"))
-        self.numx_line.setPlaceholderText(_translate("Dialog", "# pts"))
+        self.newx_log_checkbox.setText(_translate("Dialog", "log-spaced?"))
         self.curve_checkbox.setText(_translate("Dialog", "Plot fit curve"))
         self.partial_checkBox.setText(_translate("Dialog", "Plot partial functions"))
+        self.parameter_checkbox.setText(_translate("Dialog", "Plot parameter"))
 from ..lib.forms import ElideComboBox
 from pyqtgraph import GraphicsLayoutWidget
diff --git a/src/gui_qt/fit/result.py b/src/gui_qt/fit/result.py
index 17b3799..4706cbc 100644
--- a/src/gui_qt/fit/result.py
+++ b/src/gui_qt/fit/result.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from math import isnan
 
 from pyqtgraph import mkBrush, mkPen
@@ -28,6 +30,7 @@ class QFitResult(QtWidgets.QDialog, Ui_Dialog):
         self.extrapolate_box.stateChanged.connect(lambda x: self.maxx_line.setEnabled(x))
         self.extrapolate_box.stateChanged.connect(lambda x: self.minx_line.setEnabled(x))
         self.extrapolate_box.stateChanged.connect(lambda x: self.numx_line.setEnabled(x))
+        self.extrapolate_box.stateChanged.connect(lambda x: self.newx_log_checkbox.setEnabled(x))
 
         self._previous_fits = {}
         self._opts = []
@@ -352,7 +355,7 @@ class QFitResult(QtWidgets.QDialog, Ui_Dialog):
 
             parts = self.partial_checkBox.checkState() == QtCore.Qt.CheckState.Checked
 
-            extrapolate = [None, None, None]
+            extrapolate = [None, None, None, None]
             error = []
             if self.extrapolate_box.isChecked():
                 try:
@@ -368,6 +371,8 @@ class QFitResult(QtWidgets.QDialog, Ui_Dialog):
                 except (TypeError, ValueError):
                     error.append('Number of points is missing')
 
+                extrapolate[3] = self.newx_log_checkbox.isChecked()
+
             if error:
                 msg = QtWidgets.QMessageBox.warning(self, 'Error', 'Extrapolation failed because:\n' + '\n'.join(error))
                 return
@@ -405,10 +410,13 @@ class FitExtension(QtWidgets.QDialog):
         self.num_pts.setValidator(QtGui.QIntValidator())
         gridLayout.addWidget(self.num_pts, 2, 1, 1, 1)
 
+        self.logx_checkbox = QtWidgets.QCheckBox('Log-spaced?')
+        gridLayout.addWidget(self.logx_checkbox, 3, 0, 1, 2)
+
         self.buttonBox = QtWidgets.QDialogButtonBox()
         self.buttonBox.setOrientation(QtCore.Qt.Orientation.Horizontal)
         self.buttonBox.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel | QtWidgets.QDialogButtonBox.Ok)
-        gridLayout.addWidget(self.buttonBox, 3, 0, 1, 2)
+        gridLayout.addWidget(self.buttonBox, 4, 0, 1, 2)
 
         self.setLayout(gridLayout)
 
@@ -416,12 +424,13 @@ class FitExtension(QtWidgets.QDialog):
         self.buttonBox.rejected.connect(self.reject)
 
     @property
-    def values(self):
+    def values(self) -> tuple[float, float, int, bool] | None:
         try:
             xmin = float(self.min_line.text())
             xmax = float(self.max_line.text())
             nums = int(self.num_pts.text())
+            logx = self.logx_checkbox.isChecked()
         except TypeError:
             return None
 
-        return xmin, xmax, nums
+        return xmin, xmax, nums, logx
diff --git a/src/gui_qt/main/mainwindow.py b/src/gui_qt/main/mainwindow.py
index 8575319..80935b6 100644
--- a/src/gui_qt/main/mainwindow.py
+++ b/src/gui_qt/main/mainwindow.py
@@ -984,7 +984,8 @@ class NMRMainWindow(QtWidgets.QMainWindow, Ui_BaseWindow):
         res = w.exec()
         if res:
             p = w.values
-            x = linspace(p[0], p[1], num=p[2])
+            spacefunc = geomspace if p[3] else linspace
+            x = spacefunc(p[0], p[1], num=p[2])
             self.management.extend_fits(sets, x)
 
     @QtCore.pyqtSlot(name='on_action_create_fit_function_triggered')
diff --git a/src/gui_qt/main/management.py b/src/gui_qt/main/management.py
index 3185b30..b8758b2 100644
--- a/src/gui_qt/main/management.py
+++ b/src/gui_qt/main/management.py
@@ -613,7 +613,7 @@ class UpperManagement(QtCore.QObject):
                 continue
 
             if not all(e is None for e in extrapolate):
-                spacefunc = np.geomspace if fit.islog else np.linspace
+                spacefunc = np.geomspace if extrapolate[3] else np.linspace
 
                 xmin = fit.x.min()
                 xmax = fit.x.max()
diff --git a/src/resources/_ui/fitresult.ui b/src/resources/_ui/fitresult.ui
index 142a794..9f8bd4f 100644
--- a/src/resources/_ui/fitresult.ui
+++ b/src/resources/_ui/fitresult.ui
@@ -354,59 +354,26 @@
       <property name="spacing">
        <number>3</number>
       </property>
-      <item row="1" column="0">
-       <widget class="QCheckBox" name="extrapolate_box">
-        <property name="toolTip">
-         <string>Extrapolates only main function</string>
-        </property>
-        <property name="text">
-         <string>Extrapolate curves</string>
-        </property>
-       </widget>
-      </item>
-      <item row="0" column="5">
-       <widget class="QCheckBox" name="parameter_checkbox">
-        <property name="text">
-         <string>Plot parameter</string>
-        </property>
-       </widget>
-      </item>
-      <item row="1" column="6">
+      <item row="1" column="7">
        <widget class="QComboBox" name="graph_comboBox">
         <property name="enabled">
          <bool>false</bool>
         </property>
         <property name="sizePolicy">
-         <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
+         <sizepolicy hsizetype="MinimumExpanding" vsizetype="Fixed">
           <horstretch>0</horstretch>
           <verstretch>0</verstretch>
          </sizepolicy>
         </property>
        </widget>
       </item>
-      <item row="1" column="5">
-       <widget class="QCheckBox" name="graph_checkBox">
-        <property name="sizePolicy">
-         <sizepolicy hsizetype="Maximum" vsizetype="Fixed">
-          <horstretch>0</horstretch>
-          <verstretch>0</verstretch>
-         </sizepolicy>
-        </property>
-        <property name="text">
-         <string>New graph for parameter</string>
-        </property>
-        <property name="checked">
-         <bool>true</bool>
-        </property>
-       </widget>
-      </item>
       <item row="1" column="1">
        <widget class="QLineEdit" name="minx_line">
         <property name="enabled">
          <bool>false</bool>
         </property>
         <property name="sizePolicy">
-         <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
+         <sizepolicy hsizetype="Maximum" vsizetype="Fixed">
           <horstretch>0</horstretch>
           <verstretch>0</verstretch>
          </sizepolicy>
@@ -419,10 +386,45 @@
         </property>
        </widget>
       </item>
-      <item row="0" column="4" rowspan="2">
-       <widget class="Line" name="line_2">
-        <property name="orientation">
-         <enum>Qt::Vertical</enum>
+      <item row="1" column="0">
+       <widget class="QCheckBox" name="extrapolate_box">
+        <property name="toolTip">
+         <string>Extrapolates only main function</string>
+        </property>
+        <property name="text">
+         <string>Extrapolate curves</string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="3">
+       <widget class="QLineEdit" name="numx_line">
+        <property name="enabled">
+         <bool>false</bool>
+        </property>
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="placeholderText">
+         <string># pts</string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="6">
+       <widget class="QCheckBox" name="graph_checkBox">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="MinimumExpanding" vsizetype="Fixed">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="text">
+         <string>New graph for parameter</string>
+        </property>
+        <property name="checked">
+         <bool>true</bool>
         </property>
        </widget>
       </item>
@@ -432,7 +434,7 @@
          <bool>false</bool>
         </property>
         <property name="sizePolicy">
-         <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
+         <sizepolicy hsizetype="Maximum" vsizetype="Fixed">
           <horstretch>0</horstretch>
           <verstretch>0</verstretch>
          </sizepolicy>
@@ -445,20 +447,33 @@
         </property>
        </widget>
       </item>
-      <item row="1" column="3">
-       <widget class="QLineEdit" name="numx_line">
-        <property name="enabled">
-         <bool>false</bool>
-        </property>
-        <property name="placeholderText">
-         <string># pts</string>
+      <item row="0" column="5" rowspan="2">
+       <widget class="Line" name="line_2">
+        <property name="orientation">
+         <enum>Qt::Vertical</enum>
         </property>
        </widget>
       </item>
-      <item row="0" column="0" colspan="4">
+      <item row="1" column="4">
+       <widget class="QCheckBox" name="newx_log_checkbox">
+        <property name="enabled">
+         <bool>false</bool>
+        </property>
+        <property name="text">
+         <string>log-spaced?</string>
+        </property>
+       </widget>
+      </item>
+      <item row="0" column="0" colspan="5">
        <layout class="QHBoxLayout" name="horizontalLayout">
         <item>
          <widget class="QCheckBox" name="curve_checkbox">
+          <property name="sizePolicy">
+           <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
+            <horstretch>0</horstretch>
+            <verstretch>0</verstretch>
+           </sizepolicy>
+          </property>
           <property name="text">
            <string>Plot fit curve</string>
           </property>
@@ -469,6 +484,12 @@
         </item>
         <item>
          <widget class="QCheckBox" name="partial_checkBox">
+          <property name="sizePolicy">
+           <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
+            <horstretch>0</horstretch>
+            <verstretch>0</verstretch>
+           </sizepolicy>
+          </property>
           <property name="text">
            <string>Plot partial functions</string>
           </property>
@@ -476,6 +497,19 @@
         </item>
        </layout>
       </item>
+      <item row="0" column="6" colspan="2">
+       <widget class="QCheckBox" name="parameter_checkbox">
+        <property name="sizePolicy">
+         <sizepolicy hsizetype="MinimumExpanding" vsizetype="Fixed">
+          <horstretch>0</horstretch>
+          <verstretch>0</verstretch>
+         </sizepolicy>
+        </property>
+        <property name="text">
+         <string>Plot parameter</string>
+        </property>
+       </widget>
+      </item>
      </layout>
     </widget>
    </item>