Blood Donation Calculator

When did you last give blood?


What was your last donation type?

Whole Blood Donation

Typically, one US Pint (450 ml) of whole blood is taken via a needle inserted into the vein of the donor. This is a very simple and quick process that does not involve any special separation machinery.

Double Red

Also known as Apheresis, this process involves taking twice the normal amount of red blood cells from the donor. A machine is used to separate red blood cells from plasma and platelets. The red blood cells are kept and the plasma and platelets are returned to the donor. The donation process takes about 30 minutes longer than a whole blood donation.


Also known as Plateletpheresis, this process is another type of type of Apheresis, in which a machine is used to separate red blood cells from plasma and platelets. Platelets are collected and the other blood components are returned to to the donor.

Never Donated

No previous donations.

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This site is for informational purposes only. Please consult with the trained professional that will be taking your blood to be sure that your donation is safe and acceptable. This site is meant as a quick calculator to help you determine when you are eligible to donate blood after your last donation. We found that there are many sites that list the number of days required before donating blood again, but none that calculated the date when you can donate blood again based on your last donation date. We hope you like it and if you have any suggestions, please email us at