Advanced AC Calculator
Example Data Table
| Build | Armor Source | Key Inputs | Common AC | Use Case |
|---|---|---|---|---|
| Agile Rogue | Studded leather | Dexterity 18, no shield | 16 | Stealth and ranged defense |
| Shield Cleric | Scale mail | Dexterity 14, shield | 18 | Front line support |
| Plate Fighter | Plate armor | Shield, Defense style | 21 | Heavy front line tank |
| Barbarian | Unarmored defense | Dexterity 14, Constitution 16 | 15 | Unarmored melee build |
| Wizard | Mage armor | Dexterity 16, Shield spell active | 21 | Emergency defense round |
Formula Used
The calculator uses the selected AC source as the starting value. Light armor adds the full Dexterity modifier. Medium armor adds Dexterity up to the normal cap of +2, or +3 when Medium Armor Master is enabled. Heavy armor ignores Dexterity.
Unarmored formulas depend on the selected feature. Normal unarmored AC is 10 + Dexterity modifier. Barbarian style is 10 + Dexterity modifier + Constitution modifier. Monk style is 10 + Dexterity modifier + Wisdom modifier. Mage armor uses 13 + Dexterity modifier.
After the base formula, the tool adds shield, magic shield, armor bonus, fighting style, cover, spell bonuses, item bonuses, and miscellaneous bonuses. If a minimum AC floor is entered, the final result becomes the higher value.
How to Use This Calculator
Enter your character level and ability scores. Select the armor source that matches your character. Choose an unarmored option only when no armor is worn. Add shield, cover, spell, item, and feature bonuses that are active at the same time.
Press the calculate button. The result appears above the form and below the header. Review the table to see every AC component. Use the chart to compare how much each part contributes. Export the answer using CSV or PDF for character notes.
Advanced Armor Class Planning for DND 5e
Why AC Matters
Armor class is the first defense a character shows in battle. It decides whether an attack roll hits or misses. A small change can matter. One extra point can turn a deadly strike into a harmless swing.
Compare Builds Before Play
This calculator helps you compare armor choices before a session. It handles light, medium, and heavy armor. It also supports shields, cover, class features, spells, and magic bonuses. You can test a quick rogue build. You can also model a shielded cleric, plated fighter, monk, barbarian, or mage armor user.
Dexterity and Armor Limits
Dexterity is often the key input. Light armor adds the full modifier. Medium armor limits the bonus. Heavy armor ignores it. Unarmored options use special formulas. A barbarian can add Constitution. A monk can add Wisdom. Mage armor starts from a stronger base and adds Dexterity.
Read the Breakdown
The result is more useful when you read the breakdown. Base armor shows where the defense begins. Dexterity shows how agility changes the number. Shields and cover show tactical protection. Spells and magic items show temporary or permanent boosts. The chart makes these parts easy to compare.
Minimum AC Floors
Use the minimum AC field for effects that set a floor. Barkskin is a common example. If the calculated value is lower than the floor, the floor becomes the final value. This is useful for special rulings, monster traits, and homebrew options.
Table Strategy
Armor class should not be viewed alone. A high number helps, but positioning still matters. Cover may be better than standing exposed. Shields can help a front line build. Light armor may help a stealth plan. Heavy armor may reduce Dexterity value, but it can provide stable defense.
Best Workflow
For best results, enter the character stats first. Then select armor and features. Add only bonuses that are active at the same time. Some game tables may restrict stacking. Always confirm unusual effects with your Dungeon Master. The tool gives a clear estimate, but the final ruling belongs at the table. Save several examples after important level ups. Compare current gear against loot found during play. Export the result for notes. This makes planning faster, clearer, and easier for the whole party between encounters and future adventures with better confidence.
FAQs
1. What is armor class in DND 5e?
Armor class is the number an attacker must meet or beat with an attack roll. Higher AC means attacks miss more often. It comes from armor, Dexterity, shields, spells, cover, and other bonuses.
2. Does Dexterity always increase AC?
No. Light armor adds full Dexterity. Medium armor limits Dexterity. Heavy armor ignores Dexterity. Some special formulas, such as mage armor or unarmored defense, may use Dexterity differently.
3. Does a shield add AC?
Yes. A normal shield adds +2 AC while equipped. A magic shield can add its own bonus too. This calculator adds magic shield value only when the shield option is checked.
4. Can spell bonuses stack?
Some bonuses can stack, but table rulings matter. This calculator adds selected active bonuses. Do not select effects that your Dungeon Master says cannot work together at the same time.
5. How does medium armor work?
Medium armor adds Dexterity only up to a cap. The normal cap is +2. With Medium Armor Master, this calculator uses a +3 cap. Negative Dexterity still affects the result.
6. Why is my heavy armor ignoring Dexterity?
Heavy armor uses its listed AC and does not add Dexterity. A high Dexterity score can still help skills and saving throws, but it does not improve heavy armor AC.
7. What is a minimum AC floor?
A minimum AC floor sets the lowest possible final AC. If the normal result is lower, the floor replaces it. This is useful for barkskin style effects or custom rules.
8. Is this calculator final for every table?
No. It gives a structured estimate using common 5e logic. Your Dungeon Master may rule differently for magic items, homebrew, cover, features, or unusual bonus stacking.