Blood Donation Time Calcuator

Blood donation time calculator. When can you give blood again?

Blood donation is a process by which a blood donor voluntarily has blood drawn for storage in a blood bank for subsequent use in a blood transfusion.

The process of giving blood involves screening the donor, the actual donation, and a brief recovery period.

This applies to both whole blood donations and plasmapheresis (giving of plasma only)


Blood Donation Calculator

If you have recently donated blood, and would like to calculate your next elligible donation date (56 days later):

Enter date of last blood donation:


Month (1 - 12):
Day(1-31):
Year (full 4 digits):

Blood Donation

Countless lives have been saved because of blood donation. But while donating blood is relatively uncomplicated, not every one can give blood. The following guidelines from the American Red Cross are not all inclusive, but will give you a general idea.

If you suspect that you may be excluded from donating, it is important to share the information with the blood center where you go to donate. Even if you are excluded, there are things you can do to help, such as volunteering your time.

General Guidelines

To donate blood, you should be
in good health
at least 17 years old
weigh at least 110 pounds

How often can blood be donated?

People in good health who weigh at least 110 pounds can donate a unit of blood as often as every eight weeks. Some states may further limit the number and/or frequency of donations in a 12-month period.

Where can I donate blood?

You can donate blood at any blood bank in your city.

How much blood can you donate at once?

One Unit=500 ml. A unit of blood (500 ml) is a little more than a pint, and the average adult body contains 10 to 12 pints of blood. Your body makes new blood constantly, and the fluid you give will be replaced within hours.