Parent Blood Type Calculator

Understanding Blood Type Inheritance

What Determines Blood Type?

Blood type is determined by genes inherited from parents. There are two main systems:

• ABO System: Determines whether a person has A, B, AB, or O blood type.
• Rh System: Determines whether a person is Rh-positive (+) or Rh-negative (-).

ABO Blood Type Inheritance

The ABO blood type is controlled by three alleles: A, B, and O. Each person inherits one allele from each parent.

• A and B are dominant over O
• A and B are codominant with each other

Rh Factor Inheritance

The Rh factor is controlled by a single gene with two alleles: Rh+ (dominant) and Rh- (recessive).

Possible Parent Blood Types Based on Child's Blood Type

Child's Blood Type	Possible Parent Combinations
O	O and O, O and A, O and B, A and B (if both carry O)
A	A and A, A and O, A and AB, A and B
B	B and B, B and O, B and AB, A and B
AB	A and B, A and AB, B and AB, AB and AB

Remember, this calculator provides possible blood types based on basic inheritance patterns. For definitive results, genetic testing is recommended.