Blood Type Calculator

Determine possible child blood types based on parent genetics

Parent Blood Types

Select the mother's ABO and Rh blood type

Select the father's ABO and Rh blood type

Possible Child Blood Types

AB+52.7%

Population frequency: 2%

A+17.6%

Population frequency: 30%

B+17.6%

Population frequency: 8%

O+5.9%

Population frequency: 35%

AB-3.5%

Population frequency: 1%

A-1.2%

Population frequency: 8%

B-1.2%

Population frequency: 2%

O-0.4%

Population frequency: 13%

Most Likely Blood Type

AB+ with a 52.7% probability

Genetic Inheritance

Mother (A+): Possible genotypes - ABO: AA, AO, Rh: ++, +-

Father (B+): Possible genotypes - ABO: BB, BO, Rh: ++, +-

Each child inherits one allele from each parent for both ABO and Rh systems

Important Note

This calculator provides genetic probabilities only. Actual blood type must be determined by laboratory testing. In rare cases, genetic variations may affect results.

Blood Donation Compatibility

Universal Donor

O- can donate to all blood types

Universal Recipient

AB+ can receive from all blood types

Compatibility Rules

ABO System: Can only receive compatible ABO types

Rh System: Rh- can receive Rh- only, Rh+ can receive both

Donation: Must match recipient's compatibility requirements

Example Compatibility

A+

Can receive from:

O-, O+, A-, A+

Can donate to:

A+, AB+

B-

Can receive from:

O-, B-

Can donate to:

B-, B+, AB-, AB+

AB+

Can receive from:

O-, O+, A-, A+, B-, B+, AB-, AB+

Can donate to:

AB+

O-

Can receive from:

O-

Can donate to:

O-, O+, A-, A+, B-, B+, AB-, AB+

Population Frequency

O+
35%
A+
30%
O-
13%
A-
8%
B+
8%
B-
2%
AB+
2%
AB-
1%

Genetics Quick Guide

ABO System

A = AA or AO alleles

B = BB or BO alleles

AB = AB alleles

O = OO alleles

Rh System

Rh+ = ++ or +- alleles

Rh- = -- alleles

Rh- is recessive

Inheritance

Each parent contributes one allele for ABO and one for Rh to each child

Understanding Blood Type Inheritance

How Blood Types Work

Blood type is determined by the presence of specific antigens on red blood cells and antibodies in the plasma. The ABO system (A, B, AB, O) and Rh system (+, -) are the most clinically important for transfusions and pregnancy.

Genetic Inheritance Patterns

  • Dominant Alleles: A and B alleles are co-dominant
  • Recessive Alleles: O and Rh- are recessive
  • Independent Inheritance: ABO and Rh systems inherit independently
  • Mendel's Laws: Follows standard genetic inheritance patterns

Clinical Significance

Blood Transfusions

Incompatible blood types can cause serious immune reactions during transfusions.

Pregnancy Complications

Rh incompatibility between mother and baby can cause hemolytic disease of the newborn.

Organ Transplantation

ABO compatibility is crucial for successful organ transplantation.

Paternity Testing

Blood types can help exclude paternity but cannot definitively prove it.

Important Medical Considerations

Laboratory Testing Required

This calculator provides genetic probabilities only. Actual blood type must always be determined by proper laboratory testing before any medical procedures.

Rare Blood Types

Some individuals may have rare blood types or genetic variations not covered by standard ABO/Rh testing that can affect inheritance patterns.

Pregnancy Planning

Rh-negative mothers may need special monitoring and treatment during pregnancy if the father is Rh-positive to prevent complications.

Emergency Situations

In emergencies, O-negative blood can be given to anyone, but type-specific blood is always preferred when time permits proper testing.