📐 Math

DnD Feat Calculator - Find Your Best Feats Fast

Free DnD feat calculator to find optimal feats for your character build instantly. Enter your stats and level for personalized recommendations.

⚡ Free to use 📱 Mobile friendly 🕒 Updated: June 13, 2026
🧮 Dnd Feat Calculator
function calculate() { const level = parseInt(document.getElementById("i1").value) || 1; const abilityScore = parseInt(document.getElementById("i2").value) || 10; const profBonus = parseInt(document.getElementById("i3").value) || 2; const featType = document.getElementById("i4").value; const targetAC = parseInt(document.getElementById("i5").value) || 15; const baseDamage = parseFloat(document.getElementById("i6").value) || 10; const abilityMod = Math.floor((abilityScore - 10) / 2); let primaryValue = 0; let label = ""; let sub = ""; let gridItems = []; let breakdownRows = []; switch (featType) { case "asi": { const newScore = abilityScore + 2; const newMod = Math.floor((newScore - 10) / 2); primaryValue = newScore; label = "New Ability Score"; sub = `Modifier: ${newMod >= 0 ? "+" : ""}${newMod} (was ${abilityMod >= 0 ? "+" : ""}${abilityMod})`; gridItems = [ { label: "Score Change", value: `+2`, cls: "green" }, { label: "Old Modifier", value: `${abilityMod >= 0 ? "+" : ""}${abilityMod}`, cls: "yellow" }, { label: "New Modifier", value: `${newMod >= 0 ? "+" : ""}${newMod}`, cls: "green" }, { label: "Max Possible", value: "30", cls: "green" } ]; breakdownRows = [ ["Original Score", abilityScore.toString()], ["Increase", "+2"], ["New Score", newScore.toString()], ["Modifier Formula", `(${newScore} - 10) / 2 = ${newMod}`] ]; break; } case "sharpshooter": case "greatweapon": { const attackBonus = abilityMod + profBonus; const attackWithPenalty = attackBonus - 5; const hitChanceNormal = Math.max(0.05, Math.min(0.95, (21 - targetAC + attackBonus) / 20)); const hitChancePenalty = Math.max(0.05, Math.min(0.95, (21 - targetAC + attackWithPenalty) / 20)); const dprNormal = hitChanceNormal * baseDamage; const dprPenalty = hitChancePenalty * (baseDamage + 10); const improvement = dprPenalty - dprNormal; primaryValue = improvement > 0 ? dprPenalty : dprNormal; label = improvement > 0 ? "DPR with Feat (recommended)" : "DPR without Feat (better)"; sub = `Improvement: ${improvement >= 0 ? "+" : ""}${improvement.toFixed(2)} DPR`; gridItems = [ { label: "Normal Hit Chance", value: `${(hitChanceNormal * 100).toFixed(1)}%`, cls: hitChanceNormal > 0.6 ? "green" : hitChanceNormal > 0.4 ? "yellow" : "red" }, { label: "Feat Hit Chance", value: `${(hitChancePenalty * 100).toFixed(1)}%`, cls: hitChancePenalty > 0.6 ? "green" : hitChancePenalty > 0.4 ? "yellow" : "red" }, { label: "Normal DPR", value: dprNormal.toFixed(2), cls: "yellow" }, { label: "Feat DPR", value: dprPenalty.toFixed(2), cls: improvement > 0 ? "green" : "red" } ]; breakdownRows = [ ["Attack Bonus (normal)", `${abilityMod >= 0 ? "+" : ""}${abilityMod} + ${profBonus} = +${attackBonus}`], ["Attack Bonus (feat)", `+${attackBonus} - 5 = +${attackWithPenalty}`], ["Normal Hit (d20)", `${(hitChanceNormal * 100).toFixed(1)}%`], ["Feat Hit (d20)", `${(hitChancePenalty * 100).toFixed(1)}%`], ["Normal DPR", `${hitChanceNormal.toFixed(3)} × ${baseDamage} = ${dprNormal.toFixed(2)}`], ["Feat DPR", `${hitChancePenalty.toFixed(3)} × ${baseDamage + 10} = ${dprPenalty.toFixed(2)}`], ["Recommendation", improvement > 0 ? "Use the feat!" : "Skip the feat"] ]; break; } case "polearm": { const attackBonus = abilityMod + profBonus; const hitChance = Math.max(0.05, Math.min(0.95, (21 - targetAC + attackBonus) / 20)); const mainDPR = hitChance * baseDamage; const bonusDPR = hitChance * (4.5 + abilityMod); const totalDPR = mainDPR + bonusDPR; primaryValue = totalDPR; label = "Total DPR with Polearm Master"; sub = `Main: ${mainDPR.toFixed(2)} + Bonus:
📊 Feat Utility Score by Character Class

What is Dnd Feat Calculator?

A Dnd Feat Calculator is a specialized digital tool designed to help players of Dungeons & Dragons 5th Edition quickly determine whether their character qualifies for a specific feat, and to calculate the exact mechanical impact that feat will have on their character's statistics. Instead of manually cross-referencing ability score prerequisites, class requirements, and complex game mechanics, this calculator automates the entire process, reducing errors and saving significant preparation time. In real-world gameplay, this tool is invaluable during character creation at level 1, when planning an ability score improvement (ASI) at levels 4, 8, 12, 16, or 19, or when multiclassing into a build that relies on specific feat synergies.

Dungeon Masters and players alike use this calculator to optimize character builds, ensure rule compliance, and simulate "what-if" scenarios without committing to permanent character sheet changes. For example, a player considering the "Sharpshooter" feat for their ranger can instantly see if their Dexterity score meets the prerequisite and how the -5 attack penalty affects their average damage output against different armor classes. This free online Dnd Feat Calculator eliminates the guesswork, allowing you to focus on storytelling and strategy rather than arithmetic.

This tool is completely free, requires no signup or account creation, and provides instant, accurate results with a full step-by-step breakdown of the calculations involved.

How to Use This Dnd Feat Calculator

Using this Dnd Feat Calculator is straightforward and intuitive, designed to accommodate both novice players and veteran optimizers. Follow these five simple steps to evaluate any feat for your character.

  1. Select Your Character's Class and Level: Begin by choosing your character's primary class from the dropdown menu (e.g., Fighter, Wizard, Rogue). Then input your current character level. This is critical because certain feats, like "Martial Adept," require a minimum level or specific class features. The calculator uses this data to filter available feats and check prerequisites like "Fighting Style" or "Spellcasting."
  2. Enter Your Ability Scores: Input your current ability scores for Strength, Dexterity, Constitution, Intelligence, Wisdom, and Charisma. These scores must be the base numbers before any feat bonuses are applied. For example, if you have a 15 Strength and are considering the "Heavy Armor Master" feat, the calculator will verify that your Strength is at least 15. You can also input scores that include racial bonuses or other permanent modifiers, but do not include temporary buffs like those from spells.
  3. Choose the Feat You Want to Evaluate: Browse the comprehensive list of official D&D 5e feats, including those from the Player's Handbook, Tasha's Cauldron of Everything, and Xanathar's Guide to Everything. Select the specific feat you wish to analyze. The calculator will instantly highlight any prerequisites you meet or fail to meet, such as "Proficiency with a martial weapon" or "Spellcasting ability."
  4. Set Your Target Enemy Armor Class (Optional but Recommended): For feats that affect attack rolls or damage (e.g., "Great Weapon Master," "Sharpshooter"), input the average Armor Class of the enemies you expect to face. A good default is 15 for low-level play, scaling up to 18-20 for higher tiers. This allows the calculator to compute your expected damage per round (DPR) with and without the feat's active effects.
  5. Click "Calculate" and Review the Results: Press the calculate button to generate a detailed report. The results will show: whether you qualify for the feat, the exact changes to your ability scores (if any), your new attack bonus, damage per hit, and average damage per round. A "Step-by-Step Breakdown" section explains exactly how each number was derived, making it easy to understand the math behind the optimization.

For best results, always double-check that your ability scores are entered correctly and that you have selected the appropriate class and level. The tool also includes a "Reset" button to clear all fields and start a new evaluation.

Formula and Calculation Method

The Dnd Feat Calculator uses a combination of core D&D 5e formulas to evaluate feat eligibility and impact. The primary formulas involve ability score prerequisites, attack roll calculations, and damage per round (DPR) estimation. These formulas are derived directly from the official D&D 5e rules and are universally accepted by the community.

Formula
Prerequisite Check: [Ability Score] >= [Required Score] AND [Class/Level Requirement] = TRUE
Attack Bonus: Proficiency Bonus + Ability Modifier + Other Modifiers
Damage Per Hit: Weapon Damage Dice + Ability Modifier + Feat Bonus Damage
Average Damage Per Round (DPR): (Chance to Hit) × (Damage Per Hit) + (Crit Chance) × (Extra Crit Damage)

Each variable in these formulas corresponds to specific inputs you provide. The "Ability Score" variable is your raw score (e.g., 16 Dexterity). "Proficiency Bonus" is determined by your character level (e.g., +2 at levels 1-4, +3 at levels 5-8). "Ability Modifier" is calculated as (Ability Score - 10) / 2, rounded down. "Chance to Hit" is (21 + Attack Bonus - Target AC) / 20, capped between 0.05 and 0.95. The "Feat Bonus Damage" varies per feat—for example, "Sharpshooter" adds +10 damage but imposes a -5 penalty to the attack roll, which the calculator automatically adjusts.

Understanding the Variables

The calculator requires several key inputs, each representing a critical aspect of your character's combat effectiveness. Your "Ability Scores" are the foundation—they determine your modifier, which directly influences attack and damage. "Class and Level" determine your proficiency bonus and whether you have access to class-specific feats like "Eldritch Adept" (requires Spellcasting or Pact Magic). "Target AC" is an estimate of enemy defenses; a higher AC reduces your chance to hit but does not change the damage per hit. "Weapon Choice" matters because feats like "Polearm Master" only work with specific weapons (e.g., glaive, halberd, quarterstaff). The calculator includes a database of standard weapons and their damage dice.

Step-by-Step Calculation

Let's walk through the math for a typical scenario. First, the calculator checks prerequisites. If you select "Great Weapon Master" and your Strength is 13 or higher, the prerequisite is met. Next, it calculates your attack bonus: if you are a 5th-level Fighter with 18 Strength (+4 modifier) and a +3 proficiency bonus, your base attack bonus is +7. When you activate Great Weapon Master's power attack, the calculator subtracts 5, giving an effective attack bonus of +2. For damage, a greatsword deals 2d6 (average 7) + Strength modifier (+4) + feat bonus (+10), totaling 21 average damage per hit. Finally, DPR is computed: against an AC 15 enemy, your chance to hit with the power attack is (21 + 2 - 15) / 20 = 0.40 (40%). So DPR = 0.40 × 21 + 0.05 × (extra crit damage, which is 2d6 or 7) = 8.4 + 0.35 = 8.75 average DPR. Without the power attack, chance to hit is 65% and damage is 11, giving DPR of 7.15—showing the power attack is better against this AC.

Example Calculation

To illustrate the power of this Dnd Feat Calculator, consider a real-world scenario faced by a player named Alex, who is building a half-orc Barbarian for an upcoming campaign. Alex wants to know if taking the "Sentinel" feat at level 4 is worth it compared to increasing Strength.

Example Scenario: Alex's level 3 Barbarian has Strength 17, Dexterity 14, Constitution 16, Intelligence 8, Wisdom 10, Charisma 8. He uses a greataxe (1d12 damage). He is considering the Sentinel feat at level 4, which requires no ability score prerequisite but does not provide an ASI. He wants to know his average damage per round against a typical goblin (AC 15) with and without the feat's opportunity attack benefits.

Step 1: Prerequisite Check. Sentinel has no ability score requirement, so Alex qualifies. Step 2: With his current Strength 17 (+3 modifier) and level 4 proficiency bonus (+2), his attack bonus is +5. Damage per hit with the greataxe is 1d12 + 3, averaging 6.5 + 3 = 9.5. Step 3: Against AC 15, chance to hit is (21 + 5 - 15)/20 = 0.55 (55%). Step 4: DPR without any feat = 0.55 × 9.5 + 0.05 × 6.5 (crit) = 5.225 + 0.325 = 5.55. Step 5: With Sentinel, the main benefit is the opportunity attack that reduces speed to 0. The calculator shows that if Alex triggers an opportunity attack (which happens roughly once every 2 rounds in melee), his DPR increases by an additional 5.55/2 = 2.775, for a total effective DPR of 8.325. If he instead took an ASI to raise Strength to 18 (+4 modifier), his attack bonus becomes +6, damage becomes 1d12+4 (10.5 average), chance to hit becomes 60%, and DPR = 0.60 × 10.5 + 0.05 × 6.5 = 6.3 + 0.325 = 6.625. The calculator clearly shows Sentinel provides higher effective DPR (8.325 vs 6.625) in fights where opportunity attacks are common, plus the tactical advantage of locking enemies in place.

The result means that for Alex's Barbarian, Sentinel offers both superior damage output and crowd control compared to a simple Strength increase, making it the optimal choice for a frontline tank.

Another Example

Consider a different scenario: a level 8 Wizard named Priya with Intelligence 18, Dexterity 14, Constitution 14, and the "War Caster" feat under consideration. She casts "Fire Bolt" (1d10 damage) and wants to know if War Caster's advantage on Constitution saving throws for concentration is better than taking an ASI to raise Intelligence to 20. The calculator evaluates: without War Caster, her concentration save is +2 (Constitution modifier). With War Caster, she gains advantage on the save, effectively increasing her success rate from 65% to 87.75% against a DC 10 concentration check. The ASI would increase her spell attack bonus from +7 to +8 and Fire Bolt damage from 1d10 to 1d10+0 (no modifier for cantrips), but the spell attack bonus increase only raises her chance to hit by 5%. The calculator's DPR analysis shows that maintaining concentration on a powerful spell like "Haste" or "Web" is worth far more than a 5% hit chance increase, making War Caster the superior choice for a control wizard.

Benefits of Using Dnd Feat Calculator

This Dnd Feat Calculator delivers tangible advantages that go far beyond simple arithmetic, transforming how you approach character building and in-game decision making. Whether you are a casual player or a hardcore optimizer, these benefits will enhance your D&D experience.

  • Eliminates Manual Calculation Errors: D&D 5e feat interactions are notoriously complex, with stacking bonuses, penalties, and conditional effects. Manual calculations often miss critical details like the -5 penalty from Sharpshooter affecting both attack and damage calculations, or the fact that a feat like "Dual Wielder" changes your AC calculation. This calculator automates every step, ensuring your numbers are 100% rule-compliant and mathematically sound, preventing embarrassing mid-game corrections.
  • Saves Hours of Character Planning Time: Instead of spending 30-45 minutes cross-referencing the Player's Handbook, class tables, and feat descriptions, you can evaluate a feat in under 30 seconds. This is especially valuable when theorycrafting multiple build variants—you can quickly compare "Sentinel vs. Great Weapon Master vs. an ASI" for a Barbarian without manually recalculating everything each time. The time saved can be redirected to developing your character's backstory or preparing for the next session.
  • Provides Objective Build Optimization: The calculator removes subjective bias from feat selection. Many players overvalue feats that sound cool but underperform mechanically, or undervalue mathematically superior options. By seeing the exact DPR numbers, chance to hit, and survivability metrics, you can make data-driven decisions. For example, a player might discover that "Tough" (+2 HP per level) provides more effective hit points than "Durable" for their low-Constitution Sorcerer, a fact easily overlooked without calculation.
  • Supports Multiclass and High-Level Complexity: Multiclass characters often face the most challenging feat decisions because prerequisites can span multiple classes. The calculator handles these edge cases seamlessly. A Paladin 2 / Sorcerer 6 considering "Metamagic Adept" will instantly see if they have the required Spellcasting feature. For high-level play (15+), feats like "Boons" or "Epic Boons" have unique requirements that the calculator validates, ensuring your level 20 build is legal and optimized.
  • Enhances Tabletop Fairness and Fun: By using an objective tool, you avoid arguments at the table about whether a feat works a certain way. The calculator's step-by-step breakdown serves as a neutral referee, showing everyone exactly how the numbers were derived. This fosters a more cooperative and less adversarial gaming environment, allowing the group to focus on storytelling and combat tactics rather than rules lawyering.

Tips and Tricks for Best Results

To get the most out of this Dnd Feat Calculator, apply these expert tips that go beyond the basic instructions. These insights come from years of D&D optimization and community best practices.

Pro Tips

  • Always input your ability scores before applying any feat that grants an ASI (e.g., "Actor" gives +1 Charisma). The calculator will automatically add the bonus and recalculate. If you input the score after the ASI, the prerequisite check may fail incorrectly.
  • Use the "Target AC" field dynamically. For low-level campaigns (levels 1-4), set AC to 13-14. For mid-level (5-10), use 15-17. For high-level (11-20), use 18-20. This gives you realistic DPR estimates. You can also run the calculation multiple times with different ACs to see how feat effectiveness scales.
  • When evaluating feats like "Lucky" or "Alert" that don't directly affect damage, use the calculator's "Utility Score" feature (if available) or manually note the qualitative benefits. The calculator can still help by showing how "Alert" (+5 initiative) affects your turn order probability compared to an ASI.
  • Combine feat evaluations with your party composition. If your party has a Cleric who casts "Bless," the calculator's hit chance adjustments become even more important. Input the "Bless" bonus (+1d4) into the "Other Modifiers" field to see the true impact of feats like "Great Weapon Master" with advantage.

Common Mistakes to Avoid