diff --git a/invesalius/data/viewer_volume.py b/invesalius/data/viewer_volume.py
index c0b33d4..88d43d5 100755
--- a/invesalius/data/viewer_volume.py
+++ b/invesalius/data/viewer_volume.py
@@ -484,7 +484,7 @@ class SlicePlane:
             elif(plane_axis == 1):
                 orientation = "CORONAL"
                 dimen = obj.GetInput().GetDimensions()
-                number = abs(dimen[0] - number)
+                number = abs(dimen[0] - (number + 1))
             else:
                 orientation = "AXIAL"
         
--
libgit2 0.21.2