Continue with Steam Calculation
While 
lifesteal is shown as a percentage (like +20%), different sources of lifesteal do not simply add together. Instead, they 
stack multiplicatively. That means as you gain more sources of lifesteal, each new item is slightly less effective than the last.
To calculate your final lifesteal, you can use the following formula:
Total Lifesteal=1−(1−L1)×(1−L2)×(1−L3)…
(Where L is the lifesteal value of each source expressed as a decimal, e.g., 0.20 for 20%).
Example
If you have 22% 
Bullet Lifesteal from 
Fury Trance and 30% Bullet Lifesteal from 
Leech, your lifesteal is calculated as follows:
- Convert the percentages to decimals: 0.22 and 0.30.
- Subtract each from 1: (1 – 0.22) = 0.78 and (1 – 0.30) = 0.70.
- Multiply those results together: 0.78 × 0.70 = 0.546.
- Subtract that result from 1: 1 – 0.546 = 0.454.
- Your final Bullet Lifesteal is 45.4%.
Note: The in-game user interface is inconsistent with rounding, so it may display as 45% or 46%.
Lifesteal vs. Creeps
Lifesteal against creeps (non-hero units) is reduced compared to heroes:
- Bullet Lifesteal vs. creeps: 60% effectiveness (e.g., 10% lifesteal becomes 6%).
Spirit Lifesteal vs. creeps: 40% effectiveness (e.g., 10% lifesteal becomes 4%).
Bullet Lifesteal
Bullet Lifesteal returns a percentage of all outgoing 
bullet damage to the player as 
health.
Graves has 8% innate Bullet Lifesteal.
Sources
| Name |  Cost |
Category | Stat change |
|---|---|---|---|
 Active Reload |
1,600 |  Weapon |
+16% Bullet Lifesteal |
 Bullet Lifesteal |
1,600 |  Vitality |
+13% Bullet Lifesteal |
| Fury Trance |
3,200 | Vitality |
+14% Bullet Lifesteal |
| Leech |
6,400 | Vitality |
+25% Bullet Lifesteal |
 Vampiric Burst |
6,400 | Vitality |
+13% Bullet Lifesteal |
| +70% Bullet Lifesteal |
Hero Abilities
Abilities that deal 
weapon damage also provide heal from Bullet Lifesteal. Here are all of the relevant abilities.
| Hero | Ability |
|---|---|
 Venator |
 Consecrating Grenade |
| Venator |
 Gutshot |
| Venator |
 Ira Domini |
Spirit Lifesteal
Spirit Lifesteal returns a percentage of all outgoing 
spirit damage to the player as health.
Sources
| Name | Cost |
Category | Stat change |
|---|---|---|---|
 Spirit Shredder Bullets |
1,600 | Weapon |
+10% Spirit Lifesteal |
 Spirit Rend |
3,200 | Weapon |
+10% Spirit Lifesteal |
 Spiritual Overflow |
6,400 | Weapon |
+13% Spirit Lifesteal |
 Spirit Lifesteal |
1,600 | Vitality |
+13% Spirit Lifesteal |
 Infuser |
6,400 | Vitality |
+70% Spirit Lifesteal |
| Leech |
6,400 | Vitality |
+25% Spirit Lifesteal |
 Mystic Reverb |
6,400 |  Spirit |
+8% Spirit Lifesteal |
Melee Lifesteal
: Main articles: 
Melee Lifesteal, 
Lifestrike
Melee Lifesteal is only provided by 
Abrams‘s 
Infernal Resilience, and heals for a percentage of 
melee damage dealt. It functions the same as other Lifesteal effects and has 40% effectiveness against creeps.
The item 
Melee Lifesteal and its upgrade 
Lifestrike both provide a passive ability which heals the user by a percentage of their melee damage dealt, but they behave differently from Lifesteal.
These abilities activate for one melee attack, then go on cooldown for several seconds, during which no further health can be regained from melee attacks. In contrast, Bullet and Spirit Lifesteal are always active and have no cooldowns. These items also grant a flat 
healing bonus on activation, and are less effective against non-heroes.