INR levels: what's normal, high and low
A standardized version of prothrombin time. Lets PT results be compared across labs and methods.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
INR is measured with a standard blood draw; no fasting is needed. A typical reference range is 0.800 – 1.10 ratio. At TestWell it's $23.99 all-in as Prothrombin Time with INR, results in 1–3 business days, drawn at Quest. An out-of-range result is a prompt to look closer, not a diagnosis.
- Units
- ratio
- Sample
- Blood draw
- Fasting
- Not required
- Results
- 1–3 business days
- Price
- $23.99
- Labs
- Quest
INR 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+ | 0.800 – 1.10 ratio |
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 INR result may mean
Higher than 1.1 in someone not on warfarin can indicate clotting issues. Therapeutic warfarin range is typically 2.0–3.0.
What a high INR 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 INR test?
Order online, a licensed physician reviews the requisition, and you walk into a nearby lab for the draw. INR is available on its own or inside these panels — panels cost less per marker when you want the fuller picture.
| Option | Includes | Price |
|---|---|---|
| Prothrombin Time with INR | This marker only | $23.99 |
| Blood Clotting Panel | 4 tests | $149.99 |
Quest vs. Labcorp for INR: 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 | $23.99 |
| Labcorp | No | — |
| BioReference (NY & NJ) | No | — |
Need help choosing a location? Use the lab finder to see draw sites near your ZIP.
Frequently asked
Higher than 1.1 in someone not on warfarin can indicate clotting issues. Therapeutic warfarin range is typically 2.0–3.0. 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 inr?
Order in two minutes, get physician-approved, and visit a lab the same day. Starts at $23.99.