With the Free Online Blood Donor Calculator, you can determine the compatibility of blood types for donations.
If you're unsure about your blood type, you can determine it using my Blood Type Calculator.
Instructions
Select Your Blood Type: Choose your blood type from the dropdown menu. Options include A, B, AB, or O, each with a positive or negative Rh factor.
Calculate: Click on the "Calculate" button to determine compatibility.
Results: The results will display which blood types you can donate to and receive from, both for blood and plasma.