How to Find Out Your Blood Type: 5 Ways That Work
Surprisingly many adults do not know their blood type. Here are five reliable methods - from free to affordable. Updated April 2026.
Ask Your GP or Physician
Your blood type may already be on file, especially if you have ever had surgery, been pregnant, or had hospital treatment. Ask your GP, family doctor, or primary care physician to check your health records. If your type is not recorded, they can order a simple blood type test at minimal or no cost under most health insurance plans.
Advantages
Free, takes minutes, most accurate.
Limitations
Requires an appointment; type may not be on record if never tested.
Donate Blood
The simplest way to find out your blood type for free is to donate blood. After your first donation, the American Red Cross and most other blood banks will test your blood and notify you of your ABO and Rh type, usually by card, letter, or email. Eligibility requires being at least 17 years old (16 in some states with parental consent), weighing at least 110 lbs, and being in generally good health.
Advantages
Free, helps others, results are definitive clinical-grade.
Limitations
Must meet donation eligibility criteria; results take a few days.
Home Blood Type Test Kit
Several home blood-type test kits are available without a prescription, including the EldonCard (widely used in education and research settings) and similar card-based systems. These kits use a few drops of blood from a finger prick with a lancet. You apply drops to card wells pre-coated with anti-A, anti-B, and anti-D antibodies, observe which drops clump (agglutinate), and read your type from the reaction pattern. Results are available in 5-10 minutes. Accuracy is generally good for ABO, though laboratory testing remains the gold standard for clinical decisions.
Advantages
Available online or in pharmacies, fast results at home, no appointment needed.
Limitations
Small cost; finger prick required; user error is possible; not suitable for rare blood type identification.
Clinical Laboratory Test
If you prefer a medically verified result without visiting a doctor first, direct-to-consumer lab testing services (Quest Diagnostics, LabCorp, and similar) offer ABO and Rh blood typing tests. You order online, visit a local lab location for a blood draw, and receive results digitally within 1-3 business days. The cost is typically $15-$50 without insurance.
Advantages
Clinical-grade accuracy, no doctor visit needed, results delivered digitally.
Limitations
Small cost; lab visit required.
Check Existing Medical Records
If you have ever had surgery, been admitted to hospital, gone through a pregnancy, had a pre-employment medical, or served in the military, your blood type was almost certainly tested and recorded. Military ID cards in many countries include blood type. Maternity records from a previous pregnancy will include your Rh status. Surgical pre-admissions workup always includes blood typing. Ask the relevant institution or access your records through their patient portal.
Advantages
Free, already done.
Limitations
Requires access to old records; may require a request.
What 23andMe and AncestryDNA Do NOT Tell You
A common misconception: consumer genetic testing (23andMe, AncestryDNA, MyHeritage) does not typically report your ABO blood type or Rh factor. These services test for single-nucleotide polymorphisms (SNPs) associated with ancestry, certain health traits, and genetic variants - but blood type requires direct serological testing of antigens on red cell surfaces, or specific genotyping for the ABO gene that most consumer services do not perform.
Some third-party tools claim to predict blood type from raw genetic data downloaded from 23andMe or similar. These predictions are not clinical-grade and should not be relied upon for medical purposes. If you need your blood type, use one of the five methods above.
Can You Guess Your Blood Type from Your Parents'?
Not reliably. Blood type follows specific genetic inheritance rules, but without knowing your parents' exact genotypes (not just phenotypes), you cannot determine your type precisely. For example, if both your parents are A-positive, you could be A-positive, A-negative, O-positive, or O-negative depending on their hidden alleles.
Use our inheritance calculator to explore what types are possible given your parents' types - but for a definitive answer, use one of the testing methods above.