diff --git a/ntclient/services/calculate.py b/ntclient/services/calculate.py
index 4ac5b251..5bdd7108 100644
--- a/ntclient/services/calculate.py
+++ b/ntclient/services/calculate.py
@@ -18,7 +18,7 @@
 # The rep values used in the calculation
 COMMON_N_REPS_MIN = 1
 COMMON_N_REPS_MAX = 20
-COMMON_N_REPS = range(COMMON_N_REPS_MIN, COMMON_N_REPS_MAX)
+COMMON_N_REPS = range(COMMON_N_REPS_MIN, COMMON_N_REPS_MAX + 1)
 # common_n_reps = (1, 2, 3, 5, 6, 8, 10, 12, 15, 20)