How to Find Armor Class in DND [Easy Beginner’s Guide]

Armor Class (AC) is the heart of combat mechanics, influencing every attack roll and determining the chances of a hit or miss.

Here is how to find armor class in DND:

Find armor class in DND by calculating base AC from armor type plus applicable modifiers. Light armor adds full Dexterity modifier, medium adds up to +2 from Dexterity, and heavy armor adds none. Unarmored defense varies by class, often involving Dexterity.

This guide is designed to demystify AC, providing you with a clear, step-by-step explanation on all the ways to find and calculate armor class, including examples and alternative methods.

What Is Armor Class (AC)?

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Ornate and colorful Armor -- How to Find Armor Class in DND
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In D&D, Armor Class (AC) represents how difficult it is to strike a character in combat.

A higher AC means a character is more adept at dodging or deflecting attacks, while a lower AC suggests they’re more susceptible to hits.

AC is a number that attackers must meet or exceed on their attack roll to inflict damage on their target.

Standard Method to Calculate AC

The standard formula for calculating AC in D&D 5e is quite straightforward.

However, the specific calculation can vary depending on the type of armor a character wears, their Dexterity modifier, and other contributing factors such as class features or spells.

Wearing Armor

The Player’s Handbook (PHB) provides AC values for various types of armor.

Here’s the basic principle:

  • Light Armor: Adds your Dexterity modifier to the base number provided for the armor. For example, Leather armor gives a base AC of 11. If your Dexterity modifier is +3, your AC would be 14 (11 + 3).
  • Medium Armor: Allows you to add up to +2 from your Dexterity modifier to the armor’s base AC. So, if you’re wearing Chain Shirt armor (base AC 13) with a Dexterity modifier of +3, you can only add +2, making your AC 15.
  • Heavy Armor: Does not allow for the addition of your Dexterity modifier. If you’re donning Plate armor, your AC is simply the armor’s base AC, which is 18.

Without Armor

Characters not wearing armor calculate their AC differently:

  • Unarmored Defense: For characters without armor, the base AC is 10 + their Dexterity modifier. Some classes, like the Barbarian and Monk, have unique ways of calculating AC when unarmored, often incorporating other ability modifiers to increase their AC.

Examples of Calculating AC

Let’s walk through some examples to clarify the calculation of AC in various scenarios:

  1. A Rogue in Leather Armor with a Dexterity Modifier of +3:
    • Base AC for Leather armor is 11.
    • Add the Dexterity modifier (+3).
    • Total AC: 11 + 3 = 14.
  2. A Fighter in Chain Mail (Heavy Armor) with a Dexterity Modifier of +1:
    • Base AC for Chain Mail is 16.
    • Dexterity modifier does not apply to Heavy Armor.
    • Total AC: 16.
  3. A Monk with a Dexterity Modifier of +3 and a Wisdom Modifier of +2 (Unarmored Defense):
    • Base AC calculation for a Monk is 10 + Dexterity modifier + Wisdom modifier.
    • Total AC: 10 + 3 (Dex) + 2 (Wis) = 15.
  4. A Wizard with Mage Armor Spell and a Dexterity Modifier of +2:
    • The Mage Armor spell sets a base AC of 13 when not wearing armor.
    • Add the Dexterity modifier (+2).
    • Total AC: 13 + 2 = 15. This example illustrates how spells can significantly impact a character’s AC, providing a magical defense that compensates for the wizard’s lack of armor.
  5. A Druid Wearing Hide Armor (Medium Armor) with a Dexterity Modifier of +1:
    • Base AC for Hide armor is 12.
    • Add the Dexterity modifier, but only up to +2 can be added for medium armor. In this case, the modifier is +1.
    • Total AC: 12 + 1 = 13. This scenario shows the calculation for a character in medium armor, highlighting how the Dexterity modifier can partially contribute to the AC.
  6. A Paladin with Half-Plate Armor and a Dexterity Modifier of +1:
    • Base AC for Half-Plate armor is 15.
    • Add the Dexterity modifier, but only up to +2 can be added for medium armor. Here, the modifier is +1.
    • Total AC: 15 + 1 = 16. This example demonstrates medium armor where the Dexterity bonus partially contributes to the AC.
  7. A Sorcerer with a Dexterity Modifier of +3 and Wearing Bracers of Defense:
    • Base unarmored AC is 10 + Dexterity modifier.
    • Bracers of Defense provide an additional +2 to AC.
    • Total AC: 10 + 3 (Dex) + 2 (Bracers) = 15. Here, magical items supplement the character’s basic unarmored defense.
  8. A Ranger Wearing Studded Leather Armor with a Dexterity Modifier of +4:
    • Base AC for Studded Leather is 12.
    • Add the Dexterity modifier (+4).
    • Total AC: 12 + 4 = 16. This is an example of light armor where the full Dexterity modifier is applied.
  9. A Cleric with Scale Mail (Medium Armor) and a Dexterity Modifier of +0:
    • Base AC for Scale Mail is 14.
    • Dexterity modifier of +0 doesn’t affect AC in this case.
    • Total AC: 14. This scenario shows that not all armor benefits from a Dexterity modifier, particularly when the modifier is non-positive.
  10. A Warlock Using Mage Armor with a Dexterity Modifier of +2 and a Shield:
    • Mage Armor sets base AC at 13.
    • Add the Dexterity modifier (+2).
    • Using a shield provides an additional +2 to AC.
    • Total AC: 13 + 2 + 2 = 17. Combining spells and shields can effectively enhance a character’s defense beyond basic armor capabilities.

Here is video walkthrough of how to calculate AC in DND:

YouTube Video by Dungeons & Dice — How to Find Armor Class in DND

Alternative and Homebrew Ways to Calculate AC

D&D 5e encourages creativity and flexibility, allowing for alternative and homebrew methods to calculate AC.

These can provide unique gameplay experiences and customization for your campaigns. =

Always discuss with your DM before implementing these methods.

  • Magic Items and Spells: Certain magic items and spells can temporarily or permanently increase a character’s AC. For example, the Mage Armor spell sets your AC to 13 + your Dexterity modifier when you’re not wearing armor.
  • Homebrew Rules: Some DMs introduce homebrew rules for AC calculation to fit the theme of their campaign or to balance gameplay. For instance, a DM might allow characters to add a proficiency bonus to AC if it fits their campaign’s narrative.

Calculating AC Without Armor

For characters adventuring without the protection of armor, calculating AC focuses on agility and other factors:

  • Base Unarmored AC: Generally, 10 + the character’s Dexterity modifier.
  • Class Features: Classes like Barbarians and Monks use special formulas that include other ability modifiers, as mentioned earlier.
  • Natural Armor: Some races or creatures have natural armor, setting a different base AC or adding bonuses to the standard calculation.

Understanding the nuances of Armor Class enhances your gameplay, providing strategic depth to combat and character development.

Whether through standard methods, utilizing spells and magic items, or incorporating homebrew rules, mastering AC calculation allows for richer, more engaging adventures in the world of D&D.

Best Ways to Boost AC

Rouge wearing leather armor-- How to Find Armor Class in DND
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Enhancing your character’s Armor Class is a strategic advantage in D&D.

Here are the best ways to boost AC, making your character a tougher target in combat:

Upgrade Your Armor

Investing in higher-quality armor is the most straightforward way to improve AC. Moving from light to medium or heavy armor, depending on your character’s proficiency, can offer significant AC boosts.

Utilize Shields

A shield adds +2 to your AC. This bonus is applicable whether you’re wearing armor or not, making shields an excellent option for nearly all classes.

Magic Items

Magic items such as the Ring of Protection or Bracers of Defense provide bonuses to AC. These items can be invaluable for characters looking for an edge in combat.


Certain spells offer temporary AC boosts. Shield, a reaction spell, adds +5 to AC until your next turn. Shield of Faith boosts AC by +2 for its duration. Using spells strategically can turn the tide of battle.

Dexterity Enhancements

Increasing your Dexterity score not only improves AC for characters in light or medium armor but also benefits initiative rolls and certain skill checks.

Class Features

Some classes offer features that increase AC. For example, the Fighter’s “Defense” fighting style grants a +1 bonus to AC when wearing armor.

How to Calculate AC in Special Circumstances

D&D 5e encompasses a vast array of special circumstances that can affect how you calculate AC.

Here are a few scenarios:


Multiclassing can lead to unique AC calculations, especially if you gain different unarmored defense abilities. Rule of thumb: you can’t combine different unarmored defense bonuses; you must choose which one to use.

Natural Armor

Certain races, like Tortles, have natural armor, setting their base AC to a specific number that doesn’t add Dexterity modifiers unless otherwise stated. In these cases, calculate AC based on the creature’s or race’s unique rules.

Temporary Bonuses

Some conditions or powers grant temporary bonuses to AC, such as cover or spells like Barkskin. Always factor in these situational bonuses when calculating your current AC.

Final Thoughts: How to Find Armor Class in DND

There are a lot of other things you need to know about armor in DND.

For example, who can use it (and who can’t), can you sleep in it, and — what we all want to know — can zombies wear it?

Find out all of this and more in the guides below.

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D&D Player’s Handbook