DND 5E Armor Class Calculator

Build accurate AC totals for heroes and monsters. Add armor, shields, traits, magic, and cover. Export clean results for table planning and sessions fast.

Full Option AC Calculator

Formula Used

Standard armor: Armor base + allowed Dexterity modifier + shield + bonuses - penalties.

Light armor: base + full Dexterity modifier. Medium armor: base + Dexterity modifier up to +2. Heavy armor: base only.

Unarmored options: Barbarian uses 10 + Dex + Con. Monk uses 10 + Dex + Wis. Mage Armor uses 13 + Dex. Custom options use the entered base plus Dex.

How to Use This Calculator

  1. Select the AC method that matches your character or creature.
  2. Choose armor, ability scores, shield status, and magic bonuses.
  3. Add spells, cover, class features, homebrew bonuses, and penalties.
  4. Press Calculate AC to see the total above the form.
  5. Use CSV or PDF export to save the current calculation.

Example Data Table

Build Base Rule Dex Score Shield Extra Effects Expected AC
Rogue in Studded Leather 12 + Dex 18 No None 16
Fighter in Plate 18 10 Yes Defense Style 21
Wizard With Mage Armor 13 + Dex 16 No Shield Spell 21
Barbarian Unarmored 10 + Dex + Con 14 Yes Ring of Protection 17

Understanding Armor Class

Armor Class is the number an enemy attack must meet or beat. It is not a pool of health. It is a target value. Higher AC means fewer weapon hits, claws, bites, and spell attacks connect. A low number can still work, but the character will rely more on distance, cover, resistance, or healing.

Why Inputs Matter

DND 5E uses several AC rules. Some armor adds your full Dexterity modifier. Medium armor limits that bonus to two. Heavy armor ignores Dexterity. Shields add a flat bonus when carried and used. Class features can replace armor math. A barbarian can use Constitution. A monk can use Wisdom. Mage Armor and natural armor set different starting numbers.

Stacking Bonuses

The calculator separates base AC from extra bonuses. It then adds shields, magic armor, protection items, spells, cover, and custom modifiers. This helps you see every source. It also avoids hidden mistakes. A shield spell bonus is temporary. Half cover is situational. A ring of protection is usually constant while worn.

Advanced Use

Use this tool before encounters, character audits, or homebrew testing. Compare plate armor with a shield. Compare Mage Armor with Bracers of Defense. Test how Haste changes survival for one fight. Enter penalties when a condition, curse, or house rule lowers AC. Export the result when you want a quick record for a sheet, note, or table handout.

Reading the Result

The final AC is only one part of defense. Saving throws, hit points, movement, reactions, and tactics still matter. A very high AC can fail against saving throw spells. A moderate AC can be safe behind cover. Review the warning notes when a feature has limits. Then choose the combination that matches your character, item list, and current scene.

Common Table Checks

Always confirm what the character is wearing now. A shield must be held. Armor may need proficiency. Stealth disadvantage can matter during scouting. Strength requirements may reduce speed for some heavy armor. Temporary magic should be removed after its duration ends. Cover should change when the creature moves. For best results, save one export for normal travel and another for combat buffs. This creates a clean comparison for players and game masters each round.

FAQs

What does AC mean in DND 5E?

AC means Armor Class. It is the target number an attack roll must meet or exceed to hit a creature.

Does heavy armor add Dexterity?

No. Heavy armor uses its listed AC value. Dexterity does not increase or reduce that armor value in standard rules.

Does medium armor use all Dexterity?

Usually no. Medium armor adds Dexterity up to a maximum of +2, unless a special feature changes that limit.

Can a shield work with Mage Armor?

Mage Armor requires no worn armor. A shield is usually separate from armor, but the character still needs proper shield use.

Why is Bracers of Defense ignored?

Bracers of Defense normally work only when the creature wears no armor and uses no shield. The calculator follows that limit.

Does armor proficiency change AC?

No. Lack of proficiency does not reduce the AC number. It can still create serious penalties for attacks, checks, and spells.

Can two AC formulas stack?

Usually no. Different AC formulas replace each other. Choose the method that applies, then add valid bonuses afterward.

Is cover included in the final AC?

Yes, when selected. Half cover adds +2. Three-quarters cover adds +5. Remove it when the target no longer has cover.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.