Baby Blood Type Calculator

Wondering if your baby will inherit your blood type? Our Baby Blood Type Calculator uses standard genetic inheritance rules (Mendelian genetics) to predict the possible blood groups for your child. Simply select the blood type (A, B, AB, or O) and Rh factor (+ or -) for both biological parents to see the results instantly.

Baby Blood Type Calculator

See probabilities based on parent genetics

Parent 1 Blood Type
Parent 2 Blood Type
Analyzing genetics…
Likelihood of Baby’s Blood Type:
* Note on Accuracy: These probabilities assume both parents carry recessive genes (e.g., AO instead of AA, Rh+/- instead of Rh+/+). This model shows the widest range of possibilities.
Did we solve your problem today?

How Blood Type Inheritance Works

A child’s blood type is determined by the genes inherited from both parents. Each parent donates one of two "alleles" (gene variants) to their child.

  • Type A and B are dominant.
  • Type O is recessive.

For example, if a parent has Blood Type A, their genotype could be AA or AO. Because we usually don't know our exact genotype without a DNA test, this calculator shows all possible outcomes.

Can Two Positive Parents Have a Negative Child?

Yes! This is a very common question. If both parents are Rh-Positive (Rh+), they may still carry a "hidden" Rh-Negative gene. If the baby inherits the negative gene from both parents, the child will be Rh-Negative.

  • Rh+ / Rh+ Parents: Can have an Rh+ OR Rh- child.
  • Rh- / Rh- Parents: Will almost always have an Rh- child.

The "Universal Donor" Myth

  • Type O Negative is the universal donor for red blood cells (anyone can receive it).
  • Type AB Positive is the universal recipient (they can receive any blood type).

Knowing your baby's potential blood type is not just fun—it’s important for medical awareness, especially regarding Rh incompatibility (when a mother is Rh- and baby is Rh+).