How Much Blood Loss Is Fatal?
The amount of blood that a human can loose before it becomes fatal is 40% of the total body blood volume. The major part is how fast the blood loss happens.
The average human has 12 pints of blood in the body. Irreversible effects can happen when you lose 3-4 pints. If you lost 4 pints you will most likely die.
If you lose more than forty percent of the blood volume of the body could be fatal. If this type of loss is not fatal it could cause organ damage.