D&D Attack Roll Calculator

Use this D&D attack roll calculator to check whether an attack hits a target AC. Enter your attack bonus, target AC, and advantage state to see the roll needed, hit chance, crit chance, and the final d20 attack result.

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Attack Calculator

Roll Type

Ability Modifier

Proficiency Bonus

Magic/Other Bonus

Target AC

Critical Range

Attack Bonus: +6

Attack bonus = ability modifier + proficiency + other bonuses.

Roll Needed Needs 10 or higher on d20

Hit Chance 55.0%

Crit Chance 5.0%

Attack Result

Click Roll Attack to roll the d20.

d20 Roll -

Second Die -

Total + Bonus -

Outcome Awaiting roll

How to calculate a D&D attack roll

A D&D attack roll is d20 + attack bonus. The attack hits if the total meets or beats the target’s Armor Class. Your attack bonus usually comes from the relevant ability modifier plus proficiency bonus if you are proficient with the weapon or spell attack.

Attack bonus formula

Attack bonus = ability modifier + proficiency bonus + magic or feature bonuses.

Melee weapon attacks usually use Strength unless the weapon has finesse.
Ranged weapon attacks usually use Dexterity.
Spell attacks use the spellcasting ability modifier.

Recent Attack Rolls

History keeps your last eight attack rolls with total, roll type, and crit detection.

No rolls yet. Roll once to start tracking.