diff --git a/bgcval2/functions/globalVolMean.py b/bgcval2/functions/globalVolMean.py
index 5d7f9ebb..310de500 100644
--- a/bgcval2/functions/globalVolMean.py
+++ b/bgcval2/functions/globalVolMean.py
@@ -31,14 +31,17 @@
 
 import numpy as np
 from bgcval2.functions.standard_functions import choose_best_var 
+from bgcval2.functions.standard_functions import find_best_var
 
 
 def calc_vol(nc):
     """
     Calculate volume from the (grid-T) netcdf file.
     """
-    area = nc.variables['area'][:]
-    thkcello = nc.variables['thkcello'][:]
+    area_key = find_best_var(nc, ['area', 'area_grid_T'])
+    thkcello_key = find_best_var(nc, ['thkcello', 'thkcello_grid_T'])
+    area = nc.variables[area_key][:]
+    thkcello = nc.variables[thkcello_key][:]
     area = area[None, None,:, :]
     return thkcello * area