Combined adult band. LabVals does not publish separate men's, women's, or pediatric ranges for International Normalized Ratio (INR); those can be narrower than the band shown.
International Normalized Ratio (INR) reference range, specimen, and conversion details
Convert any International Normalized Ratio (INR) result between units on the unit converter.
What is the normal range for International Normalized Ratio (INR)?
The standard teaching reference range for International Normalized Ratio (INR) is 0.8-1.1 (off anticoagulation) ratio in conventional units, or 0.8-1.1 ratio in SI units. This value is measured in plasma (sodium citrate).
What is a critical International Normalized Ratio (INR) value?
For International Normalized Ratio (INR), the commonly taught critical (panic) value is: > 5.0 (high spontaneous bleeding risk). Critical results are reported to the provider immediately under your facility's policy.
Source: Adult reference values compiled from Pagana & Pagana, Mosby's Diagnostic and Laboratory Test Reference, and Fischbach & Dunning, A Manual of Laboratory and Diagnostic Tests. Reference ranges vary by laboratory, method, age, sex, and population - always use the range printed on the actual result.
Above the range
What causes a high International Normalized Ratio (INR)?
Standardizes the PT across labs; therapeutic range is usually 2.0-3.0 (2.5-3.5 for mechanical valves).
Hold warfarin and notify the provider for a high INR with bleeding.
PremiumDrill the Coagulation Studies deck
You have the International Normalized Ratio (INR) range. Premium unlocks the 7-card Coagulation Studies flashcard deck with mastery tracking, study sheets that put several panels on one printable page, and unlimited practice across all 440 quiz questions - the free round stops at 10 a day.