Reverse Blood Type Calculator - Results

📋 This is a sample result. To calculate your own, click here.

🔍

Your type: A+ × Child's type: O+

Possible blood types of the other parent:

O+

38%

A+

34%

B+

O-

A-

B-

🔬 Possible Blood Types for the Other Parent

Blood Type	% of Population
O+	38% of population
A+	34% of population
B+	9% of population
O-	7% of population
A-	6% of population
B-	2% of population

🚫 Ruled Out

These blood types are not possible for the other parent given your combination:

AB+ AB-

🧬 How Does This Work?

This reverse calculator tests every possible blood type for the other parent. For each candidate, it checks whether the combination of your blood type and theirs could genetically produce your child's blood type. If any genotype combination makes it possible, that type is included.

📋 Blood Type Inheritance Chart

This chart shows every possible baby blood type (ABO only) for all parent combinations. Probability ranges depend on whether a parent carries a hidden recessive allele.

Parents	Possible Baby Types	Not Possible
O × O	O	ABAB
O × A	OA	BAB
O × B	OB	AAB
O × AB	AB	OAB
A × A	AO	BAB
A × B	ABABO	-
A × AB	ABAB	O
B × B	BO	AAB
B × AB	ABAB	O
AB × AB	ABAB	O

Your combination is highlighted.

💉 Blood Type Compatibility

Blood type determines who you can safely donate to and receive blood from. This is important for transfusions during pregnancy complications, cesarean deliveries, or emergencies.

O-

Gives to Everyone

Gets from O-

O+

Gives to O+, A+, B+, AB+

Gets from O+, O-

A-

Gives to A-, A+, AB-, AB+

Gets from A-, O-

A+

Gives to A+, AB+

Gets from A+, A-, O+, O-

B-

Gives to B-, B+, AB-, AB+

Gets from B-, O-

B+

Gives to B+, AB+

Gets from B+, B-, O+, O-

AB-

Gives to AB-, AB+

Gets from AB-, A-, B-, O-

AB+

Gives to AB+

Gets from Everyone

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🔗 Related Tools

This calculator uses standard Mendelian genetics to determine which parent blood types are compatible with a given child's type. It can rule out impossible types but cannot identify the other parent's actual blood type. Rare genetic variants like the Bombay phenotype are not accounted for. This tool is for educational purposes only and is not a substitute for blood type testing or DNA paternity testing.