Armor
The AR # before the / indicates the armor's actual Armor Rating for the area that it protects, the # after the slash indicates its contribution to one's total (or combined average) AR (as displayed in the Character Status window), with the exception of Shields, which only list the actual AR-- see Parrying for display-AR. The number before the slash is what actually counts towards AR, the latter number is merely an approximate in-game display. Decimals are rounded to the nearest whole number in-game.
AR bonuses will not show in the Status window, or have any effect, if an item is layered over a Hit Location that is already protected by something with superior AR (e.g., stacking layers does not work). Items listed are assumed to be in perfect condition (undamaged). Also, actual AR value of certain armors may differ due to quality of workmanship and whether they are PC or game-produced.
HP= The damage capacity of the armor before breakage occurs. The AR of a piece of armor will lower as the item becomes increasingly damaged.
Arms
Armor Name STR Req. AR HP Dex Penalty
Bone Arm Plates (Irreparable) 40 30/4.4 26-30 -2
Bustier, Leather* (Irreparable) 15 13/1.9 31-37 0
Bustier, Studded* 25 16/2.4 101-115 0
Daemon Bone Arm Plates (Irreparable) 40 46/7.2 26-30 -2
Female Armor, Leather* (Irreparable) 15 13/1.9 31-37 0
Female Armor, Plate* 45 30/4.4 51-65 -5
Female Armor, Studded* 35 16/2.4 101-115 0
Leather Sleeves (Irreparable) 10 13/1.9 31-37 0
Platemail Arms 40 40/5.9 51-65 -2
Ranger Armor (rare) 25 16/2.4 36-44 0
Ringmail Sleeves 20 22/3.3 41-51 -1
Studded Sleeves 25 16/2.4 36-44 0
Body
Armor Name STR Req. AR HP Dex Penalty
Bone Armor (Breastpiece) (Irreparable) 40 30/10.7 26-30 -6
Bustier, Leather* (Irreparable) 10 13/4.7 31-37 0
Bustier, Studded* 25 16/5.7 101-115 0
Chainmail Tunic 20 28/10.0 46-58 -5
Daemon Bone Armor (Breastpiece) (Irreparable) 40 46/17.7 26-30 -6
Female Armor, Leather* (Irreparable) 15 13/4.7 31-37 0
Female Armor, Plate* 45 30/10.7 51-65 -5
Female Armor, Studded* 35 16/5.7 101-115 0
Leather Tunic (Irreparable) 15 13/4.7 31-37 0
Platemail (Breastpiece) 60 40/14.3 51-65 -8
Ranger Armor (rare) 35 16/5.7 36-44 0
Ringmail Tunic 20 22/7.9 41-51 -2
Studded Tunic 35 16/5.7 36-44 0
Hands
Armor Name STR Req. AR HP Dex Penalty
Bone Gauntlets (Irreparable) 40 30/2.1 26-30 -1
Daemon Bone Gauntlets (Irreparable) 40 46/3.5 26-30 -1
Leather Gloves (Irreparable) 10 13/0.9 31-37 0
Platemail Gloves 30 40/2.8 51-65 -2
Ranger Armor (rare) 25 16/1.1 36-44 0
Ringmail Gloves 20 22/1.5 41-51 -1
Studded Gloves 25 16/1.1 36-44 0
Head
Armor Name STR Req. AR HP Dex Penalty
Bascinet 10 18/2.4 101-115 0
Bone Helm (Irreparable) 40 30/4.1 26-30 0
Chainmail Coif 20 28/3.8 36-44 0
Close Helm 40 30/4.1 46-58 0
Daemon Bone Helm (Irreparable) 40 46/7.2 26-30 0
Helmet 40 30/4.1 46-58 0
Leather Cap (Irreparable) 15 13/1.8 31-37 0
Norse Helm 40 30/4.1 46-58 0
Open Helm 40 30/4.1 46-58 0
Orc Helm (Irreparable) 0 20/2.7 31-70 0
Plate Helm 40 40/5.4 46-58 -1
Legs/Feet
Armor Name STR Req. AR HP Dex Penalty
Bone Leg Plates (Irreparable) 40 30/6.6 26-30 -4
Chainmail Leggings 20 28/6.2 46-58 -3
Daemon Bone Leg Plates (Irreparable) 40 46/10.7 26-30 -4
Leather Leggings (Irreparable) 10 13/2.9 31-37 0
Leather Shorts (Irreparable) 10 13/2.9 31-37 0
Leather Skirt (Irreparable) 10 13/2.9 31-37 0
Platemail Legs 60 40/8.8 51-65 -6
Ranger Armor (rare) 35 16/3.5 36-44 0
Ringmail Leggings 20 22/4.8 41-51 -1
Studded Leggings 35 16/3.5 36-44 0
Neck
Armor Name STR Req. AR HP Dex Penalty
Leather Gorget (Irreparable) 10 13/0.9 31-37 0
Plate Gorget 30 40/2.8 51-65 -1
Ranger Armor (rare) 25 16/1.1 36-44 0
Studded Leather Gorget 25 16/1.1 36-44 0
Shields
Shield Name STR Req. AR HP Dex Penalty
Bronze Shield 20 10/** 26-30 0
Buckler 15 7/** 41-51 0
Chaos Shield 0 32/** 101-115 0
Heater 30 23/** 31-37 0
Kite (Metal) 30 16/** 101-115 0
Kite (Wooden) 15 12/** 46-58 0
Metal Shield 10 9/** 36-44 0
Order Shield 0 30/** 101-115 0
Wooden Shield 5 8/** 21-23 0
* This piece of armor covers both the Body and Arms. Combine the two different display-AR values in order to determine the total AR value displayed in-game.
** Display-AR varies depending on one's Parrying skill. See that section for further information.

Detailed Base AR Comparison - Metal Armor
  Ringmail Exceptional Ringmail Chainmail Exceptional Chainmail Plate Exceptional Plate
Iron
22.0
26.4
28.0
33.6
40.0
48.0
Dull Copper
24.0
28.4
30.0
35.6
42.0
50.0
Shadow
26.0
30.4
32.0
37.6
44.0
52.0
Copper
28.0
32.4
34.0
39.6
46.0
54.0
Bronze
30.0
34.4
36.0
41.6
48.0
56.0
Golden / Defense
32.0
36.4
38.0
43.6
50.0
58.0
Agapite
34.0
38.4
40.0
45.6
52.0
60.0
Verite
36.0
40.4
42.0
47.6
54.0
62.0
Guarding
37.0
-
43.0
-
55.0
-
Valorite
38.0
42.4
44.0
49.6
56.0
64.0
Hardening
42.0
-
48.0
-
60.0
-
Fortification
47.0
-
53.0
-
65.0
-
Invulnerability
52.0
-
58.0
-
70.0
-

Detailed Base AR Comparison - Leather and Bone Armor
  Leather Exceptional Leather Studded Exceptional Studded Bone Exceptional Bone
Leather
13.0
15.6
18.0
21.6
30.0
36.0
Spined / Defense
23.0
-
28.0
-
40.0
-
Horned
26.0
28.6
31.0
34.6
43.0
49.0
Guarding
28.0
-
33.0
-
45.0
-
Barbed
29.0
31.6
34.0
37.6
46.0
52.0
Hardening
33.0
-
38.0
-
50.0
-
Fortification
38.0
-
43.0
-
55.0
-
Invulnerability
43.0
-
48.0
-
60.0
-