Dota 2 Calculator: The Armor & HP Calculator Tool for Dota 2

The Armor & HP Calculator Tool

The Armor & HP Calculator Tool shows how much physical damage your armor blocks, how much damage you can really take, and whether your next gold should go into armor or HP. Pick a hero and a level, or type your own numbers. Axe did the math. Axe hurt his head. Worth it.

1. Pick a hero and a level for base values from Valve’s hero data, or switch to Custom and type any health, armor and magic resistance.
2. Click items to add their armor, health and magic resistance, or the enemy’s armor reduction.
3. Read the result: physical damage taken, your HP against physical and magic damage, where you are on the armor curve and which way the Armor or HP scale tips.

Axe explains

Armor in 10 seconds

1. 0.06the magic number in the armor formula.
2. +6%more HP vs physical per armor.
3. 25%base magic resistance for every hero.
4. 1/6armor for every point of agility.

More HP makes armor better. And the other way round.

Dota 2 armor formula

Armor changes how much physical damage you take. Attacks and physical spells are multiplied by the armor damage factor:

• Positive armor reduces physical damage. It never reaches 100%, no matter how much armor you stack.
• Negative armor increases it. The factor can go up to 2, so at most you take double damage.
• Magical and pure damage ignore armor completely. Magic resistance handles magical damage.

0.06 times armor, divided by one plus 0.06 times armor. Axe read this three times. Axe now just uses the tool.

Dota 2 armor table: damage reduction by armor

HP × is how much further your HP goes against physical damage. Bars show damage taken, the full bar is double damage.

Effective HP explained: your real HP against physical and magic damage

Effective HP is how much raw damage it takes to kill you. Against physical damage it is HP ÷ armor damage factor. For positive armor that comes out to HP × (1 + 0.06 × armor): every point of armor adds 6% of your max HP.

• 2,000 HP and 10 armor: 2,000 × 1.6 = 3,200 HP against physical damage.
• 2,000 HP and 20 armor: 2,000 × 2.2 = 4,400 HP against physical damage.
• 2,000 HP and 25% magic resistance: 2,000 ÷ 0.75 = 2,667 HP against magic damage.

The two numbers are separate. Armor does nothing against a Laguna Blade, and magic resistance does nothing against a carry’s right-click.

Armor or HP? When armor is worth more

Armor and HP multiply each other. Each point of armor adds 6% of your HP, so armor gets better the more HP you have. Each point of HP is multiplied by your armor, so HP gets better the more armor you have. The tool’s scale compares a Chainmail (+4 armor, 500 gold) with a Vitality Booster (+250 health, 1,000 gold) per 1,000 gold at your current values.

Rule of thumb: lots of HP and little armor? Buy armor. Lots of armor and little HP? Buy HP. And against a magic-heavy lineup, neither helps as much as magic resistance.

Items · Dota2FreaksAll Dota 2 items and recipesEvery item with cost, recipe and stats. Find the armor, health or magic resistance your hero needs next.→

Dota 2 armor items

Items with armor, sorted by armor per 1,000 gold. Values from Valve’s item data.

Ring of Protection+2 armor175 g11.4 / 1k

Chainmail+4 armor500 g8.0 / 1k

Platemail+10 armor1,400 g7.1 / 1k

Shiva's Guard+17 armor4,500 g3.8 / 1k

Blade Mail+7 armor2,400 g2.9 / 1k

Solar Crest+7 armor · +200 HP2,575 g2.7 / 1k

Lotus Orb+10 armor3,850 g2.6 / 1k

Buckler+1 armor425 g2.4 / 1k

Pavise+3 armor · +175 HP1,350 g2.2 / 1k

Assault Cuirass+10 armor5,125 g2.0 / 1k

Crimson Guard+6 armor · +250 HP3,725 g1.6 / 1k

Armor reduction

Armor also gets taken away. Assault Cuirass (-5 armor) and Desolator (-6 armor) are the classic item sources, and many heroes have armor reduction in their spells. Negative armor on a target makes every physical hit hurt more, which is why armor reduction and physical damage go so well together.

Magic resistance and your HP against magic

Every hero has 25% base magic resistance, plus 0.1% for every point of intelligence. Other sources stack multiplicatively: each one reduces the magic damage that is left. That is why two 20% sources give 36%, not 40%.

Glimmer Cape+20% magic resistance2,150 g40% total

Pipe of Insight+20% magic resistance3,725 g40% total

Eternal Shroud+20% magic resistance · +250 HP3,900 g40% total

Cloak+18% magic resistance900 g39% total

Mage Slayer+18% magic resistance3,100 g39% total

“Total” is a hero with 25% base magic resistance plus this one item.

Stack your magic resistance item by item in the Magic Resistance Calculator. BKB gives magic resistance and debuff immunity: the BKB Checker shows which spells still go through.

Agility, strength and your effective HP

• Strength: every point gives 22 health. Every hero starts with 120 base health on top.
• Agility: every point gives 0.167 armor (one sixth), on top of the hero’s base armor.
• Intelligence: every 10 points give 1% base magic resistance.

Highest armor at level 1: Terrorblade (9.8), Bounty Hunter (8.5), Ogre Magi (6.3), Anti-Mage (6.2), Bloodseeker (6.0). Lowest: Tiny (0.0), Skywrath Mage (0.2), Centaur Warrunner (0.5). Pick any hero in the tool to see how it grows with levels.

Armor is how much you take, attack speed is how often you hit: the Attack Speed Calculator.

Armor only helps against physical damage. The Damage Type Lookup shows which enemy spells are physical, magical or pure before you buy.

All heroes · Dota2FreaksAll Dota 2 heroes with builds and statsSee role, difficulty and item builds for every hero, including the ones that stack armor best.→

Knowing your numbers helps. Knowing which of your habits loses fights helps more. Axe's habit is fighting everything. Axe has a lot of HP. It works for Axe.

Free guide · Dota2FreaksRank Up Guide: find the one thing holding you backFive quick questions about your role, your lane and your losses. You get one habit to fix and a free mission for your next three games.→

FAQ: Axe answers questions