Blood Type System

The 8 Blood Groups

A+

A Positive

~30% of population

Can donate to: A+, AB+

A-

A Negative

~6% of population

Can donate to: A+, A-, AB+, AB-

B+

B Positive

~20% of population

Can donate to: B+, AB+

B-

B Negative

~2% of population

Can donate to: B+, B-, AB+, AB-

AB+

AB Positive

~5% — Universal Recipient

Can donate to: AB+ only

AB-

AB Negative

~1% — Rarest

Can donate to: AB+, AB-

O+

O Positive

~35% — Most common

Can donate to: A+, B+, AB+, O+

O-

O Negative

~6% — Universal Donor

Can donate to: All blood groups

Blood Compatibility Chart

Blood Type	Can Donate To	Can Receive From	Rarity
A+	A+, AB+	A+, A-, O+, O-	~30%
A-	A+, A-, AB+, AB-	A-, O-	~6%
B+	B+, AB+	B+, B-, O+, O-	~20%
B-	B+, B-, AB+, AB-	B-, O-	~2%
AB+	AB+ only	All 8 types	~5%
AB-	AB+, AB-	A-, B-, AB-, O-	~1%
O+	A+, B+, AB+, O+	O+, O-	~35%
O-	All 8 types	O- only	~6%