diff --git a/testcalculator.py b/testcalculator.py
index ccc2472..bd7272b 100644
--- a/testcalculator.py
+++ b/testcalculator.py
@@ -106,8 +106,11 @@
 
         """
         ---
+        ### See also
 
-        ### Recommended Reading 
+        [Sample size calculator](http://samplesize.rfoxdata.co.uk/)
+
+        ### Recommended Reading
 
         * [Bayesian Methods for Hackers by Cameron Davidson-Pilon]\
             (https://github.com/CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers)
@@ -118,7 +121,7 @@
         """
 
     except ValueError:
-        
+
         t = """
         <img class='error'
             src='https://www.flaticon.com/svg/static/icons/svg/595/595067.svg'>
@@ -127,12 +130,12 @@
 
         """
         An error occured, please check the test data input and try again.
-        
+
         For Bayesian calculations, the conversion rate must be between 0 and
         1.
         """
 
-    
+
 else:  # Frequentist
 
     f = Frequentist(
@@ -253,6 +256,10 @@
     """
     ---
 
+    ### See also
+
+    [Sample size calculator](http://samplesize.rfoxdata.co.uk/)
+
     ### Recommended reading
 
     * [Z-test Wikipedia](https://en.wikipedia.org/wiki/Z-test)
@@ -261,4 +268,4 @@
     * [AB test calculator by AB Testguide](https://www.abtestguide.com/calc/)
     """
 
-    # TODO: Add a sample ratio mismatch score in case of unequal samples
\ No newline at end of file
+    # TODO: Add a sample ratio mismatch score in case of unequal samples