Rheumatoid Factor levels: what's normal, high and low
An antibody often present in rheumatoid arthritis. Also seen in other autoimmune and infectious conditions.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
Rheumatoid Factor is measured with a standard blood draw; no fasting is needed. A typical reference range is 0.000 – 14.0 IU/mL. At TestWell it's $21.99 all-in as Rheumatoid Factor (RF), results in 2–4 business days, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- IU/mL
- Sample
- Blood draw
- Fasting
- Not required
- Results
- 2–4 business days
- Price
- $21.99
- Labs
- Quest or Labcorp · BioReference in NY/NJ
Rheumatoid Factor Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 0.000 – 14.0 IU/mL |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
Have a result in hand? analyze it with your AI assistant using these reviewed ranges, or run it through our explainer. Tools: look up another marker's range · convert lab units
What your Rheumatoid Factor result may mean
Can reflect rheumatoid arthritis, Sjögren's, or chronic infections. Many people with elevated RF have no disease.
What a high Rheumatoid Factor means: causes, symptoms, next steps ↓Educational only — not a diagnosis. Many factors can influence a single result. Discuss anything that concerns you with a healthcare provider.
What does a high Rheumatoid Factor mean?
Rheumatoid factor is an antibody found in about 70–80% of people with rheumatoid arthritis — but also in 5–10% of healthy people (more with age), in Sjögren's syndrome, lupus, chronic hepatitis C and other long-standing infections. A positive result is a reason to look further, especially with joint symptoms; it does not diagnose arthritis on its own. Anti-CCP is the more specific companion test.
Common causes of a high Rheumatoid Factor
- Rheumatoid arthritis
- Sjögren's syndrome, lupus, mixed connective tissue disease
- Chronic infections: hepatitis C, endocarditis, tuberculosis
- Healthy older adults (low titers)
- Chronic liver or lung disease, cryoglobulinemia
Ordered from most to least common.
Symptoms that can go with it
- Joint pain, swelling and morning stiffness lasting over an hour, often symmetric small joints
- Dry eyes and mouth (Sjögren's)
- Often none
What clinicians usually check next
- Anti-CCP antibodies, CRP and ESR
- Hepatitis C test if not known
- Rheumatology referral with joint symptoms — early treatment changes outcomes
Follow-up tests at TestWell: Body Inflammation Test (ESR) ($18.99), C-Reactive Protein (CRP) ($26.99), Rheumatoid Arthritis Antibody Test (Anti-CCP) ($32.99), Sed Rate (ESR) ($24.99).
I have a positive RF but no joint pain. Do I have rheumatoid arthritis?
Probably not. Low-level RF is common in healthy people; without symptoms and with a negative anti-CCP, most clinicians simply note it and watch.
Educational only — not a diagnosis. A single result outside the range is a prompt to look closer with a clinician.
How do you get a Rheumatoid Factor test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. Rheumatoid Factor is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Rheumatoid Factor (RF) | This marker only | $21.99 |
| Autoimmune Screening Panel | 4 tests | $86.99 |
| Autoimmune Panel | 5 tests | $129.99 |
| Autoimmune Advanced Panel | 11 tests | $159.99 |
| Total Body Essentials Panel | 39 tests | $399.99 |
Quest vs. Labcorp for Rheumatoid Factor: which lab should you pick?
Both are CLIA-certified national labs and the result is clinically equivalent, so pick whichever location is closer. Your report will print that lab's own reference range, which can differ slightly from the table above.
| Lab | Available | Price |
|---|---|---|
| Quest Diagnostics | Yes | $21.99 |
| Labcorp | Yes | $21.99 |
| BioReference (NY & NJ) | Yes | $33.99 |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Frequently asked
What does a high Rheumatoid Factor mean?
Rheumatoid factor is an antibody found in about 70–80% of people with rheumatoid arthritis — but also in 5–10% of healthy people (more with age), in Sjögren's syndrome, lupus, chronic hepatitis C and other long-standing infections. A positive result is a reason to look further, especially with joint symptoms; it does not diagnose arthritis on its own. Anti-CCP is the more specific companion test.
I have a positive RF but no joint pain. Do I have rheumatoid arthritis?
Probably not. Low-level RF is common in healthy people; without symptoms and with a negative anti-CCP, most clinicians simply note it and watch.
Do I need a doctor's order to test my rheumatoid factor?
No. TestWell's licensed physician network reviews and approves your order — usually within minutes. You can place an order online without an in-person visit or a referral from your own doctor.
How long does it take to get Rheumatoid Factor results?
Most Rheumatoid Factor results are available in 1–3 business days after your specimen arrives at the lab. You'll get an email the moment your results are ready, with everything viewable in your TestWell portal.
How much does a Rheumatoid Factor test cost?
Our Rheumatoid Factor (RF) starts at $21.99. That's the all-in price — no copays, no insurance hoops, no surprise bills. HSA and FSA cards are accepted.
Do I need to fast before my Rheumatoid Factor test?
Fasting is not required for the Rheumatoid Factor test. You can have your blood drawn any time of day.
Which lab will process my Rheumatoid Factor test?
Your test will be processed by Quest Diagnostics, Labcorp, or BioReference depending on which is closest to you and which lab carries the test. All three are CLIA-certified and trusted by hospitals nationwide. You'll choose your lab during checkout from 4,000+ locations.
Ready to test your rheumatoid factor?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $21.99.