PonyatnoHow it's calculated
Matthews formula (1985): HOMA-IR = glucose (mmol/L) × insulin (µU/mL) / 22.5. The result is rounded to two decimals.
Glucose in mg/dL is first converted to mmol/L: × 10 / 180.16 (about ÷ 18) — which is why the mg/dL version of the formula divides by about 405. Insulin in pmol/L is converted to µU/mL by dividing by 6.00. Labs use slightly different insulin factors, so your report may differ in the second decimal.
Cut-offs are those commonly used by labs and in studies of adults: below 2.5 — usual range, 2.5–2.7 — borderline, 2.7 and above — suggests insulin resistance.
What to know
What HOMA-IR shows
When you are fasting, blood sugar is held steady by insulin. If tissues start responding less well, the pancreas has to release more insulin to keep glucose where it was. So a high insulin with normal glucose is an early signal, and HOMA-IR combines both numbers into one index.
When the result is unreliable
Blood must be drawn truly fasting — 8–12 hours without food or sugary drinks — with glucose and insulin taken the same morning. After a meal the index is meaningless.
The formula does not apply to people on insulin treatment or with type 1 diabetes, to children and teenagers (insulin is naturally higher during puberty), or in pregnancy. Insulin assays are not standardised: the same blood can give different numbers in different labs. There is no single agreed cut-off — it varies between populations — so a borderline result is worth rechecking.
What usually happens next
HOMA-IR is a pointer, not a diagnosis. It is usually read together with fasting glucose, HbA1c, lipids, waist size and blood pressure. If it is raised, a doctor may suggest repeating the test or an oral glucose tolerance test.
This calculator is a reference tool, not a diagnosis. Laboratory ranges differ, and the result depends on your health, medicines and other tests. Discuss it with your doctor.
FAQ
What is a normal HOMA-IR?
Most often a value below 2.5 is considered usual; from 2.7 it suggests insulin resistance, and in between is a borderline zone. If your lab prints its own range, go by that.
How should I prepare for a HOMA-IR test?
Go in the morning after 8–12 hours without food; water is fine. Glucose and insulin are drawn at the same time. It is best to skip alcohol and hard exercise the day before.
Can I use a finger-prick or glucose meter reading?
The formula was built on lab glucose from a vein. Meters and finger-prick samples are less precise, so the index will be less accurate.
Is a high HOMA-IR with normal blood sugar dangerous?
It is a reason to look at your metabolism, not a reason to panic. A raised index often comes down with changes in diet, physical activity and weight. What exactly to do is something to decide with your doctor.
Is HOMA-IR the same as QUICKI or the glucose-to-insulin ratio?
No. They use the same two tests but different formulas and scales, and some move in the opposite direction. Do not compare them with HOMA-IR cut-offs.
Sources
Formulas and cut-offs follow clinical guidelines — see sources below.
- Matthews DR et al. Homeostasis model assessment: insulin resistance and β-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985;28(7):412–419.
- There is no single international HOMA-IR cut-off: it depends on population, age and sex (Gayoso-Diz P et al. BMC Endocr Disord. 2013;13:47). 2.5 and 2.7 are the cut-offs most often printed by laboratories and used in adult studies.