Armor Class (AC) Calculator
Calculate your character’s Armor Class in Dungeons & Dragons 5th Edition
Your Armor Class Results
Comprehensive Guide to Armor Class (AC) in D&D 5e
Armor Class (AC) represents your character’s ability to avoid being hit by attacks in Dungeons & Dragons 5th Edition. Understanding how AC is calculated is fundamental to character optimization and survival in combat. This guide covers all aspects of AC calculation, from basic rules to advanced optimization strategies.
1. The AC Formula
The basic formula for calculating Armor Class is:
AC = Base AC + Dexterity Modifier + Shield Bonus + Magic Bonuses + Other Modifiers
2. Base Armor Class Options
Your base AC depends on what armor (if any) you’re wearing:
| Armor Type | Base AC | Dex Bonus | Strength Requirement | Stealth Disadvantage |
|---|---|---|---|---|
| Unarmored | 10 | Full | None | No |
| Padded | 11 | Full | None | Yes |
| Leather | 11 | Full | None | No |
| Studded Leather | 12 | Full | None | No |
| Hide | 12 | Max +2 | None | No |
| Chain Shirt | 13 | Max +2 | None | No |
| Scale Mail | 14 | Max +2 | None | Yes |
| Breastplate | 14 | Max +2 | None | No |
| Half Plate | 15 | Max +2 | None | Yes |
| Ring Mail | 14 | None | None | Yes |
| Chain Mail | 16 | None | 13 STR | Yes |
| Splint | 17 | Max +2 | 15 STR | Yes |
| Plate | 18 | None | 15 STR | Yes |
3. Dexterity Modifier Rules
The Dexterity modifier applies differently depending on armor type:
- Light Armor: Adds full Dexterity modifier
- Medium Armor: Adds Dexterity modifier, maximum +2
- Heavy Armor: No Dexterity bonus
- Shields: Always add their bonus regardless of armor type
- Unarmored: Some classes (Barbarian, Monk) have special unarmored defense calculations
4. Special Class Features
Many classes have features that modify AC:
| Class | Feature | AC Bonus | Requirements |
|---|---|---|---|
| Barbarian | Unarmored Defense | 10 + DEX + CON | No armor, no shield |
| Monk | Unarmored Defense | 10 + DEX + WIS | No armor, no shield |
| Fighter (Battle Master) | Parry | +2 (reaction) | Weapon equipped |
| Rogue (Swashbuckler) | Elegant Maneuver | +Sneak Attack die | No heavy armor |
| Cleric | Shield of Faith | +2 | Concentration, 1 action |
| Druid | Barkskin | Sets to 16 | Concentration, 1 action |
| Warlock (Hexblade) | Armor of Hexes | +CHA to AC | Curse active |
5. Magic Items and AC
Magic items can significantly boost your AC:
- +1, +2, +3 Armor/Shields: Directly increase AC by their bonus
- Cloak of Protection: +1 to AC and saving throws
- Ring of Protection: +1 to AC and saving throws
- Bracers of Defense: +2 to AC (no shield)
- Dragon Scale Mail: 13 + DEX (no stealth disadvantage)
- Dwarven Plate: 18 AC, no stealth disadvantage
- Shield of Missiles: +4 AC against ranged attacks
6. Common AC Optimization Strategies
- Dexterity Focus: Light armor with high DEX is often better than medium/heavy armor for many builds
- Shield Mastery: A +2 shield with magic bonuses can be better than heavy armor
- Class Synergy: Monks and Barbarians benefit most from high DEX/CON/WIS
- Magic Item Stacking: Combine +3 armor with +3 shield for +6 AC
- Reaction Bonuses: Defensive Duelist, Shield spell can add temporary boosts
- Cover Usage: Three-quarters cover gives +5 AC (PHB p. 196)
- Mounted Combat: Some mounts provide AC benefits
7. Common AC Calculation Mistakes
- Forgetting DEX caps on medium armor (max +2)
- Adding DEX to heavy armor (it doesn’t apply)
- Double-counting shield bonuses from multiple sources
- Ignoring strength requirements for heavy armor
- Forgetting that some features (like Barkskin) set AC rather than add to it
- Not accounting for stealth disadvantage with certain armors
- Overlooking that some AC bonuses require concentration
8. AC by Character Level (Typical Progression)
| Level Range | Typical AC (Unoptimized) | Optimized AC | Common Sources |
|---|---|---|---|
| 1-4 | 14-16 | 18-20 | Studded leather + DEX, shield |
| 5-10 | 16-18 | 20-22 | Half plate, +1 shield, Barkskin |
| 11-16 | 18-19 | 22-24 | Plate, +2 shield, Cloak of Protection |
| 17-20 | 19-20 | 24-26+ | +3 plate, +3 shield, multiple magic items |
9. Advanced AC Tactics
For high-level play, consider these advanced strategies:
- AC Stacking: Combine multiple sources (armor, shield, ring, cloak) for +4-+6 total
- Temporary Boosts: Use Shield spell (reaction +5) with Shield of Faith (+2) for +7
- Legendary Items: Some campaigns allow for +4 or +5 armor/shields
- Class Combos: Hexblade Warlock/Monk can get very high AC with CHA+DEX+WIS
- Environmental Bonuses: Difficult terrain can impose disadvantage on attackers
- Familiar Tactics: Use the Help action to impose disadvantage on attacks
- Illusion Magic: Blur spell makes attackers roll with disadvantage
10. Official Rules References
For complete rules, refer to these official sources:
- D&D Basic Rules – Armor (D&D Beyond)
- Player’s Handbook SRD v5.1 (Wizards of the Coast PDF)
- Sage Advice Compendium (Official Rulings)
Understanding AC calculation is crucial for character survival and effectiveness in combat. By mastering these rules and optimization strategies, you can create characters that are both durable and mechanically interesting. Remember that while high AC is valuable, it’s just one part of a well-rounded defense strategy that should also include hit points, saving throws, and damage mitigation.