You select your ABO/Rh blood type from the eight standard types. The tool looks up your type in a compatibility table based on the ABO/Rh antigen system. It shows which types you can donate to (recipients who lack antibodies against your antigens), which types you can receive from, your U.S. population prevalence, and any special designation. No formula is involved — this is a reference lookup based on established immunology.
Type O- red blood cells have no A, B, or Rh antigens on their surface, so they won't trigger an immune reaction in any recipient. This makes O- blood safe for emergency transfusions when the patient's blood type is unknown.
People with AB+ blood have all three antigens (A, B, and Rh) on their red cells and produce no antibodies against any of them. They can receive red blood cells from any ABO/Rh type without rejection.
No — plasma compatibility works in reverse. AB plasma is the universal plasma donor because it contains no anti-A or anti-B antibodies. This calculator covers red blood cell compatibility only.
You can find out through a blood donation (the blood bank will tell you), a blood type test kit from a pharmacy, or by asking your doctor to include it in routine blood work. Many people learn their type during pregnancy screening.
Estimate only. Results reflect your inputs and standard formulas — they are not financial, tax, legal, health, or investment advice. Verify important decisions with a qualified professional.