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Blood Donor Calculator

Last updated: December 21, 202415 people find this calculator helpful
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Donating blood, while undoubtedly praiseworthy, can also be very confusing. Not all blood types are compatible, so you might find it impossible to donate blood to a particular person. If you are wondering who you can donate blood to or what is the universal blood donor type, look no further than this blood donor calculator.

We try our best to make our s as precise and reliable as possible. However, this tool can never replace a professional doctor's assessment.

Blood type compatibility

There are four main blood types: A, B, AB, and 0. Each of them is characterized by a different combination of antigens found on the surface of red blood cells. For example, red cells of the A blood group are covered in only A antigens, while cells of the group AB have both A and B antigens on their outer membrane.

Apart from antigens, human blood contains antibodies. Antigen A is always accompanied by antibody B, and antigen B — by antibody A. Combining antigen A with antibody A or antigen B with antibody B results in an agglutination reaction — clumping of blood particles. Because of that reaction, it's crucial only to transfer blood from a compatible donor.

Our blood type compatibility calculator takes into consideration an additional classification that divides blood into two groups: Rh+ and Rh-. Rh- blood can be received by both Rh+ and Rh- types, but Rh+ blood can only be transferred to other Rh+ types.

💡 We also have a blood type calculator, which gives you the probability that a child will have a certain blood type depending on the blood types of their parents.

Who can I donate blood to?

All of these rules sound complicated and are hard to remember. Luckily, now you can use our blood donor calculator to check whether you can donate or receive blood. If you want a visual aid, though, be sure to check out the blood compatibility chart below.

Recipient ↓ / Donor →

0+

0-

A+

A-

B+

B-

AB+

AB-

0+

Yes

Yes

No

No

No

No

No

No

0-

No

Yes

No

No

No

No

No

No

A+

Yes

Yes

Yes

Yes

No

No

No

No

A-

No

Yes

No

Yes

No

No

No

No

B+

Yes

Yes

No

No

Yes

Yes

No

No

B-

No

Yes

No

No

No

Yes

No

No

AB+

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

AB-

No

Yes

No

Yes

No

Yes

No

Yes

Universal donor blood type

As shown in the table above, blood type 0 Rh- can be considered a universal donor. This blood type can be transferred to everyone else. Following the same logic, blood type AB Rh+ is a universal recipient.

Blood plasma compatibility

If you want to transfer blood plasma, you need to follow a different set of rules. In essence, plasma compatibility is the inverse of blood compatibility. Additionally, you don't need to consider the Rh+ or Rh- classification.

The blood plasma compatibility chart looks like this:

Recipient ↓ / Donor →

0

A

B

AB

0

Yes

Yes

Yes

Yes

A

No

Yes

No

Yes

B

No

No

Yes

Yes

AB

No

No

No

Yes

Are you in search of a calculator to accurately calculate when you can donate blood next? Check out our blood donation due date calculator.

💡 You might also find our fresh frozen plasma dose calculator interesting.

FAQs

What does the Blood Donor Calculator do?
This blood donor calculator checks the compatibility for donating and receiving blood or blood plasma. Use the calculator above for instant results in your browser.
Is the Blood Donor Calculator free to use?
Yes. All Try To Calculator tools are free and do not require an account.
Are my inputs stored or sent to a server?
No. Calculations run locally in your browser. We do not collect the numbers you enter or the results shown.
Can I use the Blood Donor Calculator for professional decisions?
This tool is for education and quick estimates. For medical, legal, tax, or financial decisions, verify results with a qualified professional.
Where can I find related calculators?
Browse more Health tools on Try To Calculator at /health, or use the related calculators section on this page.

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