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.
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.
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 Panel | 49 tests | $499.99 |
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
Can reflect rheumatoid arthritis, Sjögren's, or chronic infections. Many people with elevated RF have no disease. A single result above the reference range is a prompt to look closer with a clinician — often a repeat test and related markers — not a diagnosis on its own.
Ready to test your rheumatoid factor?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $21.99.