Dnd Damage Calculator

Reviewed by Marcus Thorn, Tabletop RPG Analyst Updated: October 2023

Instantly calculate the average, minimum, and maximum damage output for your Dungeons & Dragons character attacks or spells. Use this tool to optimize your build and understand your expected damage per round (DPR).

DnD Damage Calculator

DnD Damage Calculator Formula

Avg Damage = (N × ((D + 1) / 2)) + M

Formula logic based on standard probability distributions found in the Systems Reference Document (SRD).

Variables

• N (Dice Count): The number of dice rolled (e.g., the “2” in 2d6).
• D (Dice Size): The number of faces on the die (e.g., 6 for a d6).
• M (Modifier): The flat bonus added to the roll (e.g., Strength modifier, Magic weapon bonus, Feat bonuses like GWM).

Related Calculators

• Attack Roll Probability Calculator
• Effective HP (EHP) Calculator
• Challenge Rating (CR) Calculator
• Point Buy Ability Score Calculator

What is a DnD Damage Calculator?

A DnD Damage Calculator is a tool designed for Dungeons & Dragons players and Dungeon Masters to determine the statistical output of attacks and spells. While the game relies on rolling dice for excitement, understanding the Average Damage is crucial for character optimization (min-maxing) and balancing encounters.

By inputting the dice configuration (like 8d6 for a Fireball) and flat modifiers, you can see not just the potential maximum damage, but the mathematical expectation. This helps players decide between using a Greatsword (2d6) or a Greataxe (1d12) based on consistency versus volatility.

How to Calculate DnD Damage (Example)

Let’s calculate the damage for a Level 5 Fighter using a Greatsword with 18 Strength (+4 Modifier).

1. Identify Dice: A Greatsword deals 2d6 damage. So, N = 2, D = 6.
2. Find Average Die Roll: Calculate (6 + 1) / 2 = 3.5.
3. Multiply by Count: 2 dice × 3.5 average = 7 base damage.
4. Add Modifier: Add the +4 Strength modifier. 7 + 4 = 11.
5. Result: The average damage per hit is 11.

Frequently Asked Questions (FAQ)

Why is the average of a d6 3.5 and not 3?

The average is the sum of all faces (1+2+3+4+5+6 = 21) divided by the number of faces (6). 21 / 6 = 3.5.

Does this calculator account for Critical Hits?

This module calculates standard damage. For critical hits, double the number of dice (N) in the input field before calculating.

What is better: 2d6 or 1d12?

2d6 has a higher average (7) compared to 1d12 (6.5) and is more consistent (bell curve). 1d12 has a higher variance, making it riskier but fun.

How do I add Great Weapon Master (GWM)?

Simply add +10 to the “Flat Modifier” field. Remember to account for the -5 penalty to hit separately.