diff --git a/src/_pytest/python_api.py b/src/_pytest/python_api.py
index 24145016ce6..79c21303595 100644
--- a/src/_pytest/python_api.py
+++ b/src/_pytest/python_api.py
@@ -235,7 +235,12 @@ def __repr__(self):
         # If a sensible tolerance can't be calculated, self.tolerance will
         # raise a ValueError.  In this case, display '???'.
         try:
-            vetted_tolerance = "{:.1e}".format(self.tolerance)
+            if isinstance(self.tolerance, int):
+                vetted_tolerance = "{:n}".format(self.tolerance)
+            elif self.rel is not None and not math.isinf(self.tolerance):
+                vetted_tolerance = "{:.1%}".format(self.tolerance / self.expected)
+            else:
+                vetted_tolerance = "{:.1e}".format(self.tolerance)
             if isinstance(self.expected, complex) and not math.isinf(self.tolerance):
                 vetted_tolerance += " ∠ ±180°"
         except ValueError: