WHIRLWIND EXPLANATION: Pokémon have a fixed, permanent score from 0 to 31 for each stat that affects how good that stat can ever get.

This calculator will figure out that score (called a "gene" or, more obtusely, an "IV") for you, so you can discard the unworthy. It's more accurate for higher-level Pokémon, so it's helpful to go into a level 100 wifi battle with someone and check your Pokémon's stats from there.

Stat calculator

Gloom
Gloom 		Base
stats		 Stats Effort Stats Effort Stats Effort Stats Effort Stats Effort Stats Effort Stats Effort Stats Effort Stats Effort Stats Effort Possible genes (IVs)
Level Level Level Level Level Level Level Level Level Level
HP 60
56–62
58–65
60–67
62–70
65–72
67–75
69–77
71–80
73–82
84–95
25
Attack 65
32–38
33–40
34–42
36–43
37–45
38–46
40–48
41–50
42–51
49–59
31
Defense 70
34–40
35–42
37–44
38–46
40–47
41–49
42–51
44–52
45–54
52–63
12
Special Attack 85
40–47
42–49
44–51
45–53
47–55
49–57
50–59
52–61
54–63
62–73
26
Special Defense 75
36–43
38–44
39–46
41–48
42–50
44–52
45–53
47–55
48–57
56–66
7
Speed 40
21–28
22–29
23–30
24–31
25–32
25–33
26–34
27–36
28–37
32–42
23

Congratulations, you've narrowed your Pokémon's stats down exactly!

This Gloom's Hidden Power inflicts Grass damage, with 66 power.

And for your copy/pasting pleasure:

25 HP; 31/12 Physical; 26/7 Special; 23 Speed

or start over