Blood Groups & Inheritance Calculator
Who can you save? And what blood type will your child have?
Interactive Compatibility Checker
Select a blood group below to see compatibility.
The Science of Blood
Blood types are determined by microscopic markers (Antigens) and are inherited through genes. Understanding this can save lives in emergencies and explain family traits.
The ABO System
Type A
Has A Antigens.
Hates B.
Type B
Has B Antigens.
Hates A.
Type AB
Has Both.
Accepts All.
Type O
Has None.
Gives to All.
Rare & Special Blood Types
Golden Blood (Rh-null)
Imagine having blood so rare that fewer than 50 people on Earth share it. Rh-null blood lacks all Rh antigens. It's the "universal" blood for rare types but dangerous for the owner—if they need blood, only another one of the 50 people can save them.
Hh (Bombay) Group
Discovered in Mumbai in 1952. People with this type lack the "H antigen" which is the foundation for A and B antigens. They test as Type O but **cannot** receive Type O blood. They can only receive from other Bombay donors.
Blood Type Myths vs Facts
Fact: There is no scientific evidence that your blood type affects how you digest food.
Fact: This is a cultural belief (Ketsueki-gata) with no biological basis. Your personality comes from your brain, not your blood antigens.
Frequently Asked Questions
Can two O type parents have a child with A or B blood?
No. Parents with Type O blood have only O genes (recessive). Therefore, they can only pass on O genes, so their biological child will always be Type O.
What is the "Golden Blood" type?
Rh-null is often called "Golden Blood". It is the rarest blood type in the world, lacking all 61 possible antigens in the Rh system. Fewer than 50 people worldwide are known to have it. It is the true universal blood for anyone with rare Rh types, but it is incredibly difficult to find donors for these individuals.
What is the Bombay Blood Group?
The Bombay phenotype (h/h) is an extremely rare blood type found mostly in South Asia. These individuals lack the H antigen, which is the precursor for A and B antigens. They appear to be Type O on regular tests but cannot receive Type O blood—they can only receive blood from other Bombay donors.
Does blood type determine personality?
This is a popular belief in Japanese and Korean culture (Ketsueki-gata), similar to horoscopes. However, there is no scientific evidence linking blood type to personality traits. It is purely a cultural phenomenon.
Why can't A Positive donate to A Negative?
A Positive (A+) blood contains the Rh antigen. If given to an A Negative (A-) person, their immune system will recognize the Rh antigen as foreign and attack it, causing a dangerous reaction.
How is blood type inherited?
You inherit one gene from each parent. The A and B genes are dominant, while the O gene is recessive. For example, if you get an A gene from mom and O gene from dad, you will be Type A.
What happens in a mismatched transfusion?
The recipient's immune system attacks the donated red blood cells (hemolysis). This releases toxic contents, causing fever, kidney failure, shock, and potentially death. This is why cross-matching is vital.
Why is O Negative the universal donor?
Type O- red blood cells have NO A, B, or Rh antigens on their surface. This means a recipient's immune system has nothing to "attack," making it safe for almost anyone in an emergency.
What is the blood type diet?
A diet popularized by Dr. Peter D'Adamo claiming you should eat according to your blood type. Scientific reviews have found no evidence to support these claims. A healthy, balanced diet works best for everyone regardless of blood type.
Can blood type change?
It is extremely rare, but possible. Bone marrow transplants (which produce blood cells) can change a recipient's blood type to that of the donor. Some infections can also temporarily mimic a change.