How To Calculate Armor Class In 5e

Armor Class (AC) is an essential part of any character and it determines how easily a creature can be hit. Even though it is called “armor” class, the AC does not always entirely rely on how much armor a creature is wearing which is why it’s important to calculate it. A high AC can mean that a creature is incredibly dexterous or can use magic to defend itself.

Your AC is damaged when you receive an attack, whether it be a weapon is swung, or a laser is cast. Each point of AC means an attacker must roll 1 higher to deal damage to you. But, to a new player, calculating the AC and finding ways to boost it in the future can be difficult. Check out our guide below to learn more.

How To Calculate Armor Class 5e

To calculate Armor Class, you need to remember an easy formula. At level 1, your AC has nothing going on and is straightforward as it can be. The standard AC is;

AC = 10 + Dexterity Mod

To change the AC, the base 10 number must be changed. The most common way to do this is through your armor. Below are the features of each armor and how much will be added to your armor class.

Light Armor

Padded11 + Dex mod
Leather11 + Dex mod
Studded Leather12 + Dex mod

Medium Armor (up to +2 from Dexterity Modifier)

Hide12 + Dex mod (max 2)
Chain Shirt13 + Dex mod (max 2)
Scale Mail14 + Dex mod (max 2)
Breastplate14 + Dex mod (max 2)
Half Plate15 + Dex mod (max 2)

Heavy Armor (No Dexterity modifier)

Ring Mail14
Chain Mail16

If you choose the heavier armors like the Medium and Heavy armor, it decreases the amount of Dexterity mod you can apply to your armor class, but offer higher base AC. As you choose your armor, we suggest avoiding Hide Armor or Ring Mail as they are significantly worse than Studded Leather and Breastplates/Half Plates. To add, if you provide a shield in a hand that’s not equipped with a weapon, you gain another +2 to AC. That stacks with armor class from weapons. If you’re proficient with shield, and using a 1 handed weapon, there’s no downside to wielding a shield as well.

In some rare cases, Armor and Shields can also gain numerical bonuses to AC. Enchantment bonuses can provide between +1 to +3 to your AC.

Other Ways To Calculate Armor Class

Unarmored Defense

Various classes and races also have different ways to calculate the armor class and change your base AC. The Barbarian and Monk can provide an additional statistic to their AC if they’re not wearing armor. This Unarmored Defense has the possibility of allowing the character to use Shields.

In select races, unarmored defense benefits them better. This is called Natural Armor. Like Barbarians, most characters with Natural Armor can use shields and still get an advantage.


Using a Mage Armor is the easiest way for spellcasters to get a good boost to AC that sets their base at 13, similar to the Natural Armor. A Shield gives a +5 to one attack. Meanwhile, Guardian of Faith, Haste, and Warding Bond gives a smaller but longer-lasting boost to AC. As for the highest, Barkskin sets your AC to 16.


This is a secret to getting AC. If you’re back cover that shields half of your body, you get boosted +2 AC. If your behind cover protects almost all of you, you get a +5. It’s not the most common thing to use but great to remember if you’re a ranged character

Concluding How To Calculate Armor Class

AC is easy to understand and calculate. It enables new players to easily get into the game by showing that they can significantly damage other creatures by just hitting a certain number. There’s still a lot of class features that can provide bonuses to AC that we haven’t mentioned. Make sure to do your research so your character can attack with the most damage.

Want more resources to help you calculate Armor Class? Check out this helpful thread from Reddit and watch the video below to help you get started. Happy playing!

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