diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
index 8ba6b20a9..48922b208 100644
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -34,6 +34,7 @@ set (UG_SRCS
   protocols.adoc
   logging.adoc
   make-qso.adoc
+  measurement_tools.adoc
   new_features.adoc
   platform-dependencies.adoc
   protocols.adoc
@@ -72,6 +73,9 @@ set (UG_IMGS
   images/decodes.png
   images/download_samples.png
   images/file-menu.png
+  images/FreqCal.png
+  images/FreqCal_Graph.png
+  images/FreqCal_Results.png
   images/freemsg.png
   images/ft8_decodes.png
   images/help-menu.png
diff --git a/doc/user_guide/en/images/FreqCal_Results.png b/doc/user_guide/en/images/FreqCal_Results.png
new file mode 100644
index 000000000..d1e93f5c8
Binary files /dev/null and b/doc/user_guide/en/images/FreqCal_Results.png differ
diff --git a/doc/user_guide/en/measurement_tools.adoc b/doc/user_guide/en/measurement_tools.adoc
index 756724b29..1dc367c7d 100644
--- a/doc/user_guide/en/measurement_tools.adoc
+++ b/doc/user_guide/en/measurement_tools.adoc
@@ -56,6 +56,7 @@ measurements, as shown for these measurements in the graph plotted
 below.  Software tools for completing this task are included with the
 _WSJT-X_ installation, and detailed instructions for their use are
 available at https://physics.princeton.edu/pulsar/k1jt/FMT_User.pdf.
+
 Using these tools and no specialized hardware beyond your
 CAT-interfaced radio, you can calibrate the radio to better than 1 Hz
 and compete very effectively in the ARRL's periodic Frequency
@@ -63,6 +64,17 @@ Measuring Tests.
 
 image::FreqCal_Graph.png[align="left",alt="FreqCal_Graph"]
 
+After running *Execute frequency calibration cycle* at least once with
+good results, the line-fitting procedure can be carried out
+automatically by clicking *Solve for calibration parameters* on the
+*Tools* menu.  The results will be displayed as in the following
+screen shot.  Estimated uncertainties are included for slope and
+intercept; `N` is the number of averaged frequency measurements included
+in the fit, and `StdDev` is the root mean square deviation of
+averaged measurements from the fitted straight line.  
+
+image::FreqCal_Results.png[align="center",alt="FreqCal_Results"]
+
 === Reference Spectrum
 
 _WSJT-X_ provides a tool that can be used to determine the detailed
diff --git a/mainwindow.cpp b/mainwindow.cpp
index bc4b71384..e1490fed0 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -2113,7 +2113,7 @@ void MainWindow::on_actionSolve_FreqCal_triggered()
   strncpy(data_dir,dpath.toLatin1(),len);
   calibrate_(data_dir,&iz,&a,&b,&rms,&sigmaa,&sigmab,&irc,len);
   QString t1;
-  t1.sprintf("Slope:     %10.3f ±%7.3f ppm\nIntercept:  %7.2f ±%5.2f    Hz\n\nNgroups:   %6d\nStdDev:  %8.2f  Hz",
+  t1.sprintf("Slope:     %10.3f ±%7.3f ppm\nIntercept:  %7.2f ±%5.2f    Hz\n\nN:   %18d\nStdDev:  %8.2f  Hz",
              b,sigmab,a,sigmaa,iz,rms);
   QString t2{"Solution looks good."};
   if(irc<0) t1="";