How to Calculate AC 5e: A Comprehensive Guide for Dungeons & Dragons Players

how to calculate ac 5e

How to Calculate AC 5e: A Comprehensive Guide for Dungeons & Dragons Players

In the world of Dungeons & Dragons (5th Edition), Armor Class (AC) is a crucial defensive statistic that determines a character’s ability to avoid being hit by attacks. A high AC makes it harder for enemies to hit you, reducing the chances of them dealing damage.

Calculating AC in 5e is a simple process that involves combining various factors, including your character’s armor, Dexterity modifier, and other modifiers. Understanding how to calculate AC is essential for creating an effective character that can withstand the challenges of combat.

Transition paragraph: Now, let’s delve into the details of calculating AC in 5e, breaking down each component and providing examples to ensure a clear understanding.

How to Calculate AC 5e

To calculate Armor Class (AC) in Dungeons & Dragons 5th Edition, consider the following eight important points:

  • Base AC
  • Armor Bonus
  • Dexterity Modifier
  • Shield Bonus
  • Natural Armor
  • Magic Armor
  • Temporary Bonuses
  • Class Features

By combining these factors, you can determine your character’s AC, which plays a crucial role in defending against attacks and enhancing survivability in combat.

Base AC

Base AC represents the core defensive value of a character before considering any modifiers or equipment. It forms the foundation upon which other AC components are added.

  • 10 + Dexterity Modifier

    For most characters, their Base AC is calculated by adding 10 to their Dexterity modifier. Dexterity is a key ability score that influences a character’s agility, reflexes, and balance, making it crucial for AC.

  • Natural Armor

    Certain races, such as Dragonborn and Tortles, possess natural armor that provides a bonus to their Base AC. This bonus is inherent to their race and does not require any equipment or proficiencies.

  • Unarmored Defense

    Monks and certain subclasses, like the Barbarian’s Unarmored Defense feature, can use their Wisdom or Constitution modifier, respectively, instead of Dexterity for calculating their Base AC. This allows them to excel in combat without relying on heavy armor.

  • Other Class Features

    Some classes, such as the Fighter’s Defense fighting style, gain additional bonuses to their Base AC. These class features further enhance their defensive capabilities.

Your Base AC serves as the starting point for calculating your total AC, which can be further modified by equipping armor, shields, and other defensive items or abilities.

Armor Bonus

Armor Bonus represents the AC bonus gained from wearing protective gear, such as armor, shields, or clothing with inherent defensive properties. It plays a significant role in enhancing a character’s ability to withstand attacks.

The Armor Bonus depends on the type and quality of armor worn. Light armor, such as leather or studded leather, provides a modest AC bonus while allowing for greater mobility. Medium armor, like chain shirts or breastplates, offers a more substantial AC boost but may hinder movement slightly. Heavy armor, such as plate mail, grants the highest AC bonus but comes at the cost of reduced speed and agility.

When determining your Armor Bonus, consider the following factors:

  • Armor Proficiency: To gain the full benefit of an armor’s AC bonus, you must be proficient with the armor type. Proficiency can be obtained through class features, feats, or backgrounds.
  • Armor Class: Each type of armor has a base AC value. This value is added to your Base AC to determine your total AC.
  • Armor Enhancements: Some magical armor or armor modifications can provide additional bonuses to AC, further enhancing your defenses.

Choosing the right armor is crucial for optimizing your character’s AC. Consider your character’s class, playstyle, and combat role when selecting armor. A balance between mobility and protection is often the key to effective defense.

Your Armor Bonus, combined with your Base AC and other modifiers, contributes to your total AC, which determines your character’s overall ability to avoid being hit by attacks.

Dexterity Modifier

The Dexterity Modifier is a crucial component of Armor Class, particularly for characters who rely on agility and reflexes to avoid attacks.

  • Base Dexterity Score: Your Dexterity score, determined during character creation or ability score improvement, serves as the foundation for your Dexterity Modifier.
  • Modifier Calculation: To calculate your Dexterity Modifier, subtract 10 from your Dexterity score. The result is your Dexterity Modifier, which can be a positive or negative value.
  • AC Contribution: Your Dexterity Modifier is added to your Base AC to determine your total AC. A higher Dexterity Modifier means a higher AC, making you harder to hit.
  • Evasion and Reflexes: Dexterity Modifier also contributes to your character’s ability to evade attacks and react quickly in combat. It influences skills like Acrobatics, Stealth, and Initiative.

Dexterity Modifier is especially important for classes that prioritize agility, such as Rogues, Monks, and Rangers. By investing in Dexterity, these classes can significantly enhance their AC and combat prowess.

Shield Bonus

A Shield Bonus provides additional AC when wielding a shield in one hand. Shields are defensive items that offer protection against melee and ranged attacks.

To determine your Shield Bonus, consider the following factors:

  • Shield AC: Each shield has a base AC bonus associated with it. This bonus ranges from +1 to +5, depending on the shield’s material and quality.
  • Shield Proficiency: To gain the full benefit of a shield’s AC bonus, you must be proficient with shields. Proficiency can be obtained through class features, feats, or backgrounds.
  • Shield Disadvantages: Some shields may have disadvantages associated with them, such as a higher weight or a penalty to Dexterity checks. Consider these factors when choosing a shield.

When you wield a shield in one hand and have the other hand free, you gain the Shield Bonus to your AC. This bonus is added to your Base AC, Armor Bonus, and Dexterity Modifier to determine your total AC.

Shields are particularly useful for characters who engage in melee combat, as they provide an extra layer of protection against incoming attacks. However, they can also be beneficial for spellcasters and ranged attackers who want to boost their AC without sacrificing mobility.

By combining your Shield Bonus with other AC components, you can significantly enhance your character’s ability to withstand damage and emerge victorious in combat.

Natural Armor

Natural Armor represents the inherent defensive capabilities of certain creatures, granting them a bonus to their AC without the need for external armor.

Natural Armor is determined by a creature’s race or class features. For example, Dragonborn possess scales that provide them with a natural AC bonus, while Tortles have tough shells that enhance their AC.

To determine your Natural Armor bonus, consider the following factors:

  • Race or Class Features: Check your race or class description to see if you have a Natural Armor bonus. This bonus is typically a fixed value, such as +1 or +2.
  • Unarmored Defense: Some classes, such as Monks, can use their Dexterity or Wisdom modifier to calculate their AC instead of wearing armor. This is known as Unarmored Defense and can provide a Natural Armor bonus.
  • Natural Armor Enhancements: Certain magical items or abilities can enhance your Natural Armor bonus, further increasing your AC.

Natural Armor is a valuable defensive trait that can significantly boost your AC, especially in the early stages of the game when you may not have access to powerful armor or magical items.

By combining your Natural Armor bonus with other AC components, you can create a resilient character capable of withstanding a variety of attacks and emerging victorious from combat.

Magic Armor

Magic Armor refers to armor imbued with magical properties, providing additional defensive benefits beyond its normal AC bonus.

Magic Armor can be found as loot, purchased from merchants, or crafted by skilled artisans. It comes in various forms, including enchanted plate mail, shimmering chain shirts, or even magical robes.

To determine the AC bonus granted by Magic Armor, consider the following factors:

  • Armor Class: Magic Armor typically has a base AC value, similar to non-magical armor. This value is added to your Base AC to determine your total AC.
  • Magical Properties: Magic Armor often possesses special abilities or enchantments that enhance its defensive capabilities. These properties can include resistance to certain damage types, bonuses to saving throws, or even the ability to cast spells.
  • Rarity: The rarity of Magic Armor (common, uncommon, rare, very rare, or legendary) generally indicates the potency of its magical properties.

Magic Armor can significantly enhance your character’s survivability in combat. By equipping magical armor, you can gain powerful defensive abilities that protect you from a wide range of threats.

However, keep in mind that Magic Armor is often more expensive and difficult to obtain than non-magical armor. It is important to weigh the benefits of Magic Armor against its cost and availability when making your choice of defensive gear.

Temporary Bonuses

Temporary Bonuses are short-duration effects that can enhance your AC for a limited time. These bonuses can come from various sources, such as spells, class features, or magical items.

To determine the AC bonus granted by Temporary Bonuses, consider the following factors:

  • Source of Bonus: Identify the source of the Temporary Bonus, such as a spell, class feature, or magical item. Each source has its own rules and limitations.
  • Bonus Value: The AC bonus granted by Temporary Bonuses varies depending on the source. It can be a fixed value, a modifier based on your ability scores, or a special effect.
  • Duration: Temporary Bonuses typically have a limited duration, ranging from a few rounds to an entire encounter. Pay attention to the duration of the bonus to make the most of it.

Temporary Bonuses can provide a significant boost to your AC, helping you survive dangerous encounters and emerge victorious from combat.

However, it is important to remember that these bonuses are temporary and will eventually expire. Plan your combat strategy accordingly, and be prepared to adjust your tactics once the bonuses fade away.

Class Features

Certain classes in Dungeons & Dragons 5e possess class features that can enhance their AC beyond the standard calculation methods. These features provide unique defensive abilities that complement the class’s combat style and role.

To determine the AC bonus granted by Class Features, consider the following factors:

  • Class and Level: Identify the class and level of your character. Specific class features become available at certain levels, so check your class description to see if you have any AC-related features.
  • Feature Description: Read the description of the class feature carefully to understand how it affects your AC. Some features grant a fixed bonus, while others might scale with your level or other factors.
  • Activation and Duration: Pay attention to any conditions or limitations associated with the class feature. Some features may require activation or have a limited duration, so plan accordingly.

Class Features can significantly enhance your AC, providing additional protection and survivability in combat.

However, it is important to note that not all classes have AC-related features. If your class does not have such features, focus on optimizing your AC through other means, such as selecting the right armor, using shields, and enhancing your Dexterity score.


Have questions about calculating Armor Class in Dungeons & Dragons 5e? Check out these frequently asked questions:

Question 1: Why is my AC different from my friend’s AC, even though we have the same armor?

Answer: Your AC is determined by several factors, including your Dexterity modifier, armor bonus, and other modifiers. If you have different ability scores or are wearing different armor, your AC will be different.

Question 2: How do I calculate my AC if I’m wearing a shield?

Answer: If you are proficient with shields and are wielding one in one hand, you add the shield’s AC bonus to your AC.

Question 3: What is Natural Armor, and how does it affect my AC?

Answer: Natural Armor is a bonus to AC that some creatures have due to their natural features, such as scales or thick hide. If you have Natural Armor, add the bonus to your AC.

Question 4: Can I use my Dexterity modifier to calculate my AC even if I’m wearing heavy armor?

Answer: No, you cannot use your Dexterity modifier to calculate your AC if you are wearing heavy armor. Heavy armor imposes a disadvantage on Dexterity-based ability checks, including AC.

Question 5: What are some ways to improve my AC?

Answer: There are several ways to improve your AC, including increasing your Dexterity score, wearing better armor, using a shield, and acquiring magical items that enhance your AC.

Question 6: How does Temporary AC work, and how long does it last?

Answer: Temporary AC is a bonus to AC that lasts for a limited duration, typically a number of rounds or until the start of your next turn. Temporary AC can come from spells, abilities, or magical items.

Remember, understanding how to calculate AC is crucial for optimizing your character’s defenses and surviving the perils of your D&D adventures!

Now that you have a better understanding of AC calculation, let’s explore some additional tips for enhancing your character’s defenses:


To further enhance your understanding of AC calculation and improve your character’s defenses, consider these practical tips:

Tip 1: Choose the Right Armor:

Select armor that suits your character’s class, playstyle, and Dexterity score. Consider the AC bonus, armor proficiency, and any special abilities the armor provides.

Tip 2: Prioritize Dexterity:

Invest in increasing your Dexterity score whenever possible. A higher Dexterity modifier improves your AC, initiative, and several skills.

Tip 3: Utilize Shields:

If your character can wield a shield, take advantage of the AC bonus it provides. Shields offer a simple yet effective way to boost your defenses.

Tip 4: Seek Magical Items and Class Features:

Keep an eye out for magical items and class features that enhance your AC. These can provide significant bonuses and unique defensive abilities.

Remember, AC is a crucial aspect of your character’s survivability. By following these tips, you can optimize your AC and become a formidable force on the battlefield!

With a solid understanding of AC calculation, practical tips for improvement, and an arsenal of defensive strategies, you’re well-equipped to protect your characters and conquer the challenges that lie ahead in your D&D adventures!


Throughout this guide, we delved into the intricacies of calculating Armor Class (AC) in Dungeons & Dragons 5th Edition. We explored the various components that contribute to AC, including Base AC, Armor Bonus, Dexterity Modifier, Shield Bonus, Natural Armor, Magic Armor, Temporary Bonuses, and Class Features.

By understanding how these components work together, you can optimize your character’s AC and significantly enhance their survivability in combat. Remember, a high AC makes it harder for enemies to hit you, reducing the damage you take and increasing your chances of emerging victorious from battles.

So, equip your character with the best armor, shields, and magical items you can find, invest in Dexterity, and take advantage of class features that enhance your AC. With a well-calculated AC, you’ll be a formidable force on the battlefield, ready to face any challenge that comes your way.

May your adventures be filled with triumph and glory, and may your AC always protect you from harm!

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