D&D 5e Armor Class (AC) Calculator

An essential tool for every Dungeons & Dragons 5th Edition player. Instantly calculate your character’s AC based on armor, stats, and more.

What is Armor Class (AC) in D&D 5e?

Armor Class (AC) is a fundamental mechanic in Dungeons & Dragons 5th Edition that represents how difficult it is to hit a character or creature with an attack. When an attack is made, the attacker rolls a 20-sided die (d20) and adds their relevant attack modifiers. If the total result equals or exceeds the target’s AC, the attack hits. A higher AC means a character is better at avoiding or deflecting blows, making them more durable in combat.

This value isn’t just about the armor you wear; it’s a combination of physical protection, agility, magical enhancements, and even innate toughness. For example, a heavily armored knight might have a high AC due to their plate mail, while a nimble rogue has a high AC from expertly dodging attacks. Our ac 5e calculator helps you easily determine this crucial number by taking all relevant factors into account.

The Formula for AC in 5e

AC isn’t a single formula but a set of calculations depending on what your character is wearing. This is a core part of the system, and understanding it is key. Here’s a breakdown of the most common AC calculations:

• Unarmored: 10 + Dexterity modifier. This is the baseline for any creature without armor.
• Light Armor: Base AC from armor + Dexterity modifier.
• Medium Armor: Base AC from armor + Dexterity modifier (to a maximum of +2).
• Heavy Armor: Base AC from armor. Dexterity is not added.
• Shield: +2 to AC. This bonus stacks with armor.
• Special Cases: Some classes, like Barbarian or Monk, have “Unarmored Defense” features that provide alternative AC calculations. Spells like Mage Armor also provide a unique formula.

Variables Table

Key variables used in the ac 5e calculator and their typical ranges.

Variable	Meaning	Unit	Typical Range
Base AC	The starting AC value from armor or an unarmored state.	AC Points	10 – 18
Ability Score	A character’s core statistic (e.g., Dexterity).	Score	3 – 20 (can go higher)
Ability Modifier	The bonus/penalty derived from an Ability Score.	Bonus	-4 to +5 (or more)
Shield Bonus	The fixed AC bonus for using a shield.	AC Points	+2

Practical Examples

Let’s see the ac 5e calculator in action with two different character builds.

Example 1: The Agile Rogue

A Level 5 Rogue with a Dexterity score of 18 (+4 modifier) wears Studded Leather armor.

• Inputs: Armor (Studded Leather), Dexterity Score (18), No Shield.
• Calculation: Studded Leather gives a base AC of 12. As light armor, it allows the full Dexterity modifier.
• Formula: 12 (Base AC) + 4 (Dexterity Bonus) = 16.
• Result: The Rogue has an AC of 16.

Example 2: The Stalwart Cleric

A Level 3 Cleric with a Strength of 16 wears Chain Mail and carries a Shield. Their Dexterity is 10 (+0 modifier).

• Inputs: Armor (Chain Mail), Dexterity Score (10), Shield (Yes), Other Bonus (0).
• Calculation: Chain Mail is heavy armor with a base AC of 16. It does not allow a Dexterity bonus. The shield adds +2.
• Formula: 16 (Base AC) + 2 (Shield Bonus) = 18.
• Result: The Cleric has an AC of 18.

How to Use This AC 5e Calculator

Using this calculator is a simple, step-by-step process:

1. Select Armor/Method: Choose your character’s armor from the dropdown. If they are unarmored, select the appropriate method (standard, Barbarian, or Monk).
2. Enter Ability Scores: Input your character’s raw Dexterity score. Add Constitution or Wisdom if you selected a corresponding Unarmored Defense method. The calculator automatically computes the modifiers.
3. Check the Shield Box: If your character is using a shield, check the box to add the +2 bonus.
4. Add Other Bonuses: Enter any miscellaneous bonuses from spells, magic items, or class features into the “Other Bonuses” field.
5. View Your Results: The calculator updates in real-time, showing your total AC and a breakdown of its components instantly.

Key Factors That Affect Armor Class

• Armor Choice: The most direct factor. The trade-off is often between protection, cost, and requirements like Strength or stealth penalties.
• Dexterity Score: Crucial for unarmored and light/medium armor users. A high Dexterity represents your ability to dodge attacks.
• Shields: A simple and effective way to get a +2 AC bonus, but it occupies one hand.
• Class Features: Features like a Barbarian’s Unarmored Defense or a Fighter’s Defense Fighting Style can significantly boost AC. For help creating a character, see these resources on the D&D Character Sheets.
• Feats: Certain feats like Defensive Duelist or Medium Armor Master can enhance your defensive capabilities.
• Spells & Magic Items: Temporary spells like Shield or permanent items like a Ring of Protection are common ways to increase AC, often taking characters into the 20+ range. Learning how to calculate AC in 5e is essential for any player.

Frequently Asked Questions (FAQ)

Q: Do you add your proficiency bonus to AC?

A: No. You do not add your proficiency bonus to your Armor Class. You only need to be proficient in the armor type you are wearing to avoid penalties. For more details check the official Player’s Handbook.

Q: Can different AC calculations stack? For example, Mage Armor and Bracers of Defense?

A: No. Different AC calculations do not stack. You must choose which formula to use. For example, if you have Mage Armor (AC 13 + Dex) and a Monk’s Unarmored Defense (AC 10 + Dex + Wis), you choose whichever gives a higher result. Bonuses (like from a shield or Ring of Protection), however, do stack on top of your chosen calculation.

Q: What is the maximum Dexterity bonus for medium armor?

A: When wearing medium armor, you can add your Dexterity modifier to your AC, but only up to a maximum of +2.

Q: Does heavy armor get a Dexterity bonus?

A: No, heavy armor does not benefit from your Dexterity modifier. Its base AC is high to compensate. A negative Dexterity modifier also does not penalize heavy armor AC.

Q: What happens if I wear armor I’m not proficient with?

A: You have disadvantage on any ability check, saving throw, or attack roll that involves Strength or Dexterity, and you can’t cast spells.

Q: How does the Defense Fighting Style work?

A: While you are wearing armor, you gain a +1 bonus to AC. This is a flat bonus that you would add to the “Other Bonuses” field in our ac 5e calculator.

Q: What’s a good AC for a level 1 character?

A: A good starting AC is typically between 14 and 18, depending on your class and build. A cleric in chain mail with a shield can start at 18, while a wizard might start around 13.

Q: How does cover affect AC?

A: Cover provides a bonus to AC against ranged attacks. Half cover gives +2, three-quarters cover gives +5, and total cover means you cannot be targeted directly.