Skyrim Armor Rating Calculator

How armor rating is calculated

Each piece of armor has a base rating. Your armor skill, smithing improvements and perks all build on that number. For one piece the game works it out like this:

Piece rating = ⌈(base + smithing bonus) × (1 + 0.4 × armor skill ÷ 100)⌉ × fit perk × Matching Set × Juggernaut or Agile Defender

• Armor skill adds up to 40% at skill 100. Fortify Heavy Armor or Fortify Light Armor enchantments and potions count as extra skill points, so they can push this above 40%.
• Juggernaut (heavy) and Agile Defender (light) add 20% per rank, up to double at rank 5. They do not apply to shields.
• Well Fitted (heavy) and Custom Fit (light) add 25% when your head, chest, hands and feet are all of that armor type.
• Matching Set adds another 25% when those four pieces all come from the same set.

Your displayed armor rating is the total of every piece, plus effects such as the Lord Stone (+50) or Oakflesh and the other flesh spells.

Damage reduction and the 567 armor cap

Armor rating turns into damage reduction at a fixed rate: each point blocks 0.12% of physical damage. Each worn piece of armor, including a shield, also adds a hidden 3%. The total is capped at 80%:

Damage reduction = displayed rating × 0.12% + 3% × pieces worn (max 80%)

Armor rating only works against physical attacks: weapons, arrows, claws and fists. Spells and dragon breath ignore it, so pair a heavy armor build with magic resistance.

Worked example: full Daedric armor

A warrior with Heavy Armor 100 wears a Daedric helmet (base 23), cuirass (49), gauntlets (18) and boots (18). Without perks or smithing, the skill bonus alone gives 33 + 69 + 26 + 26 = 154 armor rating, which blocks 154 × 0.12 + 12 = about 30% of physical damage.

Now improve every piece to Legendary at a workbench with Smithing 100 and the Daedric Smithing perk (+20 to the chest, +10 to the others), and take Juggernaut 5/5 and Well Fitted. The helmet becomes ⌈33 × 1.4⌉ × 1.25 × 2 = 117.5, the cuirass 242.5 and each gauntlet and boot piece 100: a total of 560. That blocks 79.2%, just short of the cap. Adding Matching Set, a shield or the Lord Stone puts it over.

Smithing quality

The improvement from a workbench depends on your effective Smithing skill, which the right perk doubles and Fortify Smithing gear and potions raise further:

Quality = ⌊(effective Smithing + 38) × 3 ÷ 103⌋

Quality keeps going up past Legendary with very high effective skill, adding 3.6 to chest pieces and 1.8 to the others per level. The bonus is added before the skill multiplier, so it grows with every other bonus you have.

Tips

• Don't overshoot the cap. Past 80% extra armor does nothing. Spend those perk points on skills that help elsewhere, or drop the shield for a second weapon.
• Light armor can cap too. Legendary Dragonscale at Light Armor 100 with Agile Defender 5/5 and Custom Fit comes to about 465. Matching Set takes it to about 581, over the cap.
• Plan the whole tree. See every armor perk in the Heavy Armor and Light Armor trees, or add them to a build in the build planner.