D&D Multi-Attack Damage Calculator

Model expected damage per round for Extra Attack, Multiattack, or dual wielding. Enter attack bonus, target AC, damage dice, and crit range to get instant DPR, hit chance, and max damage values.

Attack Parameters

Damage Summary

Hit Chance -
Crit Chance -
Expected DPR -
Damage / Attack -
Max Single Attack -
Max All Attacks -

Enter your build to see detailed averages, crit math, and DPR.

Recent Calculations

Stores the last eight calculations so you can compare fighting styles or weapon swaps.

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How to Use the Multi-Attack Calculator

  1. Enter the number of attacks granted by Extra Attack, Multiattack, off-hand strikes, or bonus-action attacks.
  2. Add your total attack bonus (ability modifier + proficiency + magic weapon bonuses) and the target’s Armor Class.
  3. Define weapon damage dice, optional bonus dice like Hunter’s Mark, and your static damage modifier.
  4. Select the critical range (20 for most builds, 19-20 for expanded crit features) and whether the roll has advantage or disadvantage.
  5. Press Calculate Multi-Attack or hit the space bar to instantly see hit chance, crit chance, expected damage per attack, total DPR, and theoretical maximums.

Features for Martial Classes

  • Accurate Hit Math: Uses true d20 probabilities with automatic natural 1 failures and natural 20 successes.
  • Advantage/Disadvantage Support: Calculates the adjusted probabilities for crits and hits when rolling twice.
  • Flexible Dice Inputs: Model versatile weapons, great weapon master, smites, sneak attack, Hunter’s Mark, or elemental weapon dice.
  • History Tracking: Compare up to eight previous calculations when testing fighting styles, feats, or new weapons.
  • Max Damage Insights: Display the best single attack and full-round totals when every roll crits—great for nova rounds and smite stacks.

D&D 5e Rules Behind the Numbers

In D&D 5e, every attack roll is a d20 modified by your attack bonus. A natural 1 always misses, while a natural 20 always hits and becomes a critical hit. Most classes gain Extra Attack at level 5, giving two attacks per Attack action. Some monsters have Multiattack that grants two or more strikes with a single action. Bonus actions (such as off-hand dual-wield attacks or Polearm Master butt strikes) add even more attack instances per round.

Critical hits double the damage dice but not your static modifiers. Improved Critical (Champion fighter) expands the crit range to 19-20, while certain magic items or house rules might go to 18-20. Advantage means you roll twice and keep the higher result, which increases both hit chance and crit chance; disadvantage does the opposite.

Tips, Examples, and Strategy

A level 11 Fighter with Extra Attack (3) swinging a greatsword with Strength +5 and a +2 weapon attacks four times each round (three from the attack action, one from Polearm Master or bonus attack). Plug in 4 attacks, +11 attack bonus, target AC 18, weapon dice 2d6, and a +7 damage modifier. If you add a d6 from Hexblade’s Curse or Hunter’s Mark, include that under Bonus Dice. Need advantage? Toggle it when a spell like Faerie Fire or the Help action is active. Use this calculator alongside the attack roller to resolve each strike, then confirm burst damage with the critical hit calculator if you land a nat 20. Dungeon Masters can evaluate monster multiattacks versus player AC to ensure encounter balance without complicated spreadsheets.

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