diff --git a/pokedex/formulae.py b/pokedex/formulae.py
index 19ed568..62271f1 100644
--- a/pokedex/formulae.py
+++ b/pokedex/formulae.py
@@ -18,24 +18,29 @@ def nCr(n, r):
         1)
 
 
-def calculated_stat(base_stat, level, iv, effort):
+def calculated_stat(base_stat, level, iv, effort, nature=None):
     """Returns the calculated stat -- i.e. the value actually shown in the game
     on a Pokémon's status tab.
     """
 
     # Remember: this is from C; use floor division!
-    return (base_stat * 2 + iv + effort // 4) * level // 100 + 5
+    stat = (base_stat * 2 + iv + effort // 4) * level // 100 + 5
 
-def calculated_hp(base_hp, level, iv, effort):
+    if nature:
+        stat = int(stat * nature)
+
+    return stat
+
+def calculated_hp(base_stat, level, iv, effort, nature=None):
     """Similar to `calculated_stat`, except with a slightly different formula
     used specifically for HP.
     """
 
     # Shedinja's base stat of 1 is special; its HP is always 1
-    if base_hp == 1:
+    if base_stat == 1:
         return 1
 
-    return (base_hp * 2 + iv + effort // 4) * level // 100 + 10 + level
+    return (base_stat * 2 + iv + effort // 4) * level // 100 + 10 + level
 
 def earned_exp(base_exp, level):
     """Returns the amount of EXP earned when defeating a Pokémon at the given