D&D 5E Armor Class Calculator

The D&D 5E Armor Class Calculator estimates your defensive score based on armor type, dexterity, and shields. This tool helps players and Dungeon Masters determine combat survivability and optimize character builds. Whether you are building a tanky fighter, an agile rogue, or calculating situational bonuses like cover, this tool ensures your character is ready for battle. It simplifies complex rules so you can focus on the game.

Determines how Dexterity modifier affects your AC
The base AC value from your armor or class feature
Your Dexterity modifier (can be negative)
Check if your character is wielding a shield
From feats, spells, magic items, or class features
Cover provides additional protection against attacks

How Armor Class Is Calculated

Armor Class (AC) represents the target number enemies must roll to hit your character in combat. This calculation uses the standard D&D 5th Edition rules to ensure your stats are accurate during gameplay.

AC = Base Armor + Dex (Capped) + Shield + Cover

Calculation Steps:

  • Start with your Base Armor value, which is determined by the specific gear you wear or special abilities like Unarmored Defense.
  • Apply your Dexterity Modifier to the total, but remember that Medium Armor caps this bonus at +2 and Heavy Armor ignores it completely.
  • Finally, add any flat bonuses to your score, such as +2 for a shield or situational bonuses from cover to see your final defense rating.

What Your Armor Class Means

Your Armor Class score directly impacts how often enemies land a hit on your character during a fight. A higher number means you are harder to hit, which significantly increases your survivability and reduces the need for healing.

Frontline Tank (17-20 AC)

With this high score, standard monsters struggle to hit you. You should position yourself between enemies and your party's spellcasters to absorb damage.

Squishy Caster (12-15 AC)

You are at higher risk of taking damage from weapon attacks. You must rely on terrain for cover and keep allies between you and danger.

Important: It is vital to remember that AC only protects against attack rolls. It offers no protection against spells that require a saving throw or effects like Magic Missile that hit automatically.

This tool follows the standard rules found in the Player's Handbook. However, your Dungeon Master may use specific house rules or homebrew items that modify how these calculations work in their campaign.

Check your AC calculation every time you acquire a magic item, change armor, or gain an ability score improvement to ensure your character sheet remains accurate.

Related Calculators

Calculation logic verified using publicly available standards.

View our Accuracy & Reliability Framework →