Blood Type Inheritance Calculator
ABO Blood Type Inheritance
Predict the possible blood types of a child from parent blood types using Mendelian genetics.
Formula
ABO inheritance follows Mendelian genetics with three alleles (A, B, O). A and B are co-dominant over O. Genotype possibilities: Type A = AA or AO, Type B = BB or BO, Type AB = AB, Type O = OO. Rh follows simple dominant/recessive with D (positive) dominant over d (negative).
Frequently Asked Questions
How is blood type inherited?
Blood type is determined by the ABO gene on chromosome 9. There are three alleles: A, B, and O. A and B are co-dominant (both expressed when present), while O is recessive. Each parent contributes one allele. For example, a parent with type A blood can be genotype AA or AO.
Can two type O parents have a child with a different blood type?
No, under standard genetics. If both parents are type O (genotype OO), all children will be type O. However, extremely rare genetic variants (like Bombay phenotype or cis-AB) can produce unexpected results.
What is the Rh factor?
The Rh factor (Rh D antigen) is a protein on the surface of red blood cells. If present, you are Rh positive (+); if absent, Rh negative (-). The Rh gene (RHD) has two alleles: D (dominant, Rh+) and d (recessive, Rh-). Two Rh negative parents will always have Rh negative children.
You may also need
H
Baby Weight & Length Percentile Calculator
Free online baby weight and length percentile calculator based on WHO growth charts for ages 0-24 months.
HealthH
Pregnancy Weight Gain Tracker
Free online pregnancy weight gain calculator by trimester based on IOM guidelines and pre-pregnancy BMI.
HealthH
Life Expectancy Calculator
Free online life expectancy estimator based on age, sex, lifestyle, and health factors.
Health