Is donating blood considered tzedakah? If so, what is its monetary value?
Nothing, if you don’t need it. Trillions, if you or someone close to you is in desperate need of your blood type.
I am not sure but I would think it is under Gemilas chesed and not tzedakkah,. Monetary value, to someone who needs a blood transfusion, priceless.
Why would it?
Anyways it should be considered הצלת נפשות
In most states and many countries, hospitals are not allowed to charge for blood that was donated to them. Those places usually charge about $125 for blood collection costs. In places where they are allowed to charge for blood, the cost can be anywhere between $300 to $800 a pint. Platelets are $1200.
As far as the actual question being asked here ask a Rav and let us know what he says.
The value of the blood can be someone’s life.
As far as donation value, I’ve seen the blood bank vans parked outside of Kohl’s and they give you a $10 gift card (and a cookie!) for donating. BlueClaws stadium in Lakewood offers a pair of free tickets ($20) if you donate there.