Insulin Resistance
(HOMA-IR) Calculator
Calculate your HOMA-IR score instantly using fasting glucose and fasting insulin values — with clinically referenced interpretation and actionable insights.
Calculate Your HOMA-IR Score
Enter your fasting blood test results below. Both values must be taken after at least 8 hours of fasting for accurate results.
🩸 Fasting Blood Glucose—
HOMA-IR Reference Ranges
These ranges are based on published population studies. Individual lab reference ranges may vary.
Insulin Resistance (HOMA-IR) Calculator: Check Your Metabolic Health
Insulin resistance is one of the most prevalent and underdiagnosed metabolic conditions of our time — affecting an estimated 40% of adults worldwide, often without any obvious symptoms. It sits at the root of type 2 diabetes, metabolic syndrome, non-alcoholic fatty liver disease, polycystic ovary syndrome (PCOS), and cardiovascular disease. The HOMA-IR score is the most widely used clinical tool to quantify insulin resistance from a simple fasting blood test. This free HOMA-IR calculator gives you your score instantly and explains exactly what it means.
Quick answer: HOMA-IR = (Fasting Insulin × Fasting Glucose) ÷ 405. A score below 1.0 is optimal, 1.0–1.9 is normal, 1.9–2.9 is borderline, and 2.9 or above indicates significant insulin resistance (5.0+ is very high). Example: insulin = 12 µIU/mL, glucose = 105 mg/dL → HOMA-IR = (12 × 105) ÷ 405 = 3.11 — elevated. Use the calculator above for your result.
How the HOMA-IR Calculator Formula Works
This calculator measures how efficiently your body responds to insulin, using two values from a single fasting blood draw: your glucose and your insulin. The formula multiplies the two together, then divides by 405, a constant chosen so the result lines up with clinically established reference ranges. The unit for the result is dimensionless (just a number, not a currency or percentage). Read a lower score as better insulin sensitivity and a higher score as your pancreas working harder to keep glucose in check. The formula assumes both values were measured after a genuine 8 hour fast; eating, coffee, or even stress before the blood draw can distort the glucose or insulin reading and produce a misleading score.
Identify the inputs
You enter fasting glucose (in mg/dL or mmol/L) and fasting insulin (in µIU/mL), both from the same blood test.
Apply the formula
If glucose was entered in mmol/L, the calculator first converts it to mg/dL by multiplying by 18.016. Then: HOMA-IR = (Insulin × Glucose in mg/dL) ÷ 405.
Perform the calculation
Using the example above: insulin 12 µIU/mL, glucose 105 mg/dL. (12 × 105) ÷ 405 = 1,260 ÷ 405 = 3.11.
Interpret the result
3.11 falls in the “Elevated” category (2.9 and above), meaning this person’s cells are showing significant resistance to insulin’s effects, a marker worth discussing with a healthcare provider.
3 Real-Life Examples
1. A healthy result from a routine check-up
Someone gets a routine metabolic panel and their fasting glucose comes back at 80 mg/dL with fasting insulin of 4 µIU/mL.
A score below 1.0 indicates excellent insulin sensitivity. Both individual values also fall comfortably within their normal reference ranges, which is a reassuring, consistent picture.
2. Converting a result reported in mmol/L
Someone in a country that reports glucose in mmol/L gets a fasting glucose of 5.8 mmol/L and fasting insulin of 15 µIU/mL, using the mmol/L unit toggle.
Even though the glucose reading of 5.8 mmol/L looks unremarkable on its own (normal range is roughly 3.9 to 5.5 mmol/L, so this is only slightly elevated), the fasting insulin of 15 pushes the combined HOMA-IR score into the elevated range, illustrating why insulin alone or glucose alone can miss what the combined score reveals.
3. An older adult with insulin approaching the caution threshold
A 52-year-old has fasting glucose of 110 mg/dL and fasting insulin of 18 µIU/mL, entering age in the optional field.
At 52, the calculator’s insight text notes that age itself is an independent risk factor for insulin resistance, alongside the elevated score and a glucose reading already in the prediabetes range (100 to 125 mg/dL), a combination worth raising with a doctor.
What Is Insulin Resistance?
Insulin resistance is a condition in which your body’s cells — particularly muscle, liver, and fat cells — do not respond efficiently to insulin. Normally, insulin acts like a key that unlocks your cells to let glucose in for energy. When cells become resistant, the pancreas compensates by producing more insulin to achieve the same effect.
This creates a harmful cycle:
- Cells resist insulin → blood glucose starts to rise
- Pancreas detects high glucose → secretes more insulin
- High insulin drives fat storage and inflammation
- Over time, pancreatic beta cells exhaust → glucose can no longer be controlled → type 2 diabetes
The dangerous thing about insulin resistance is that it progresses silently for years. Blood glucose can appear normal (because the pancreas is compensating with excess insulin) while metabolic dysfunction is already well underway — which is why measuring fasting insulin alongside fasting glucose is so much more informative than glucose alone.
What Is HOMA-IR?
HOMA-IR stands for Homeostatic Model Assessment of Insulin Resistance. It was developed in 1985 by Matthews et al. at Oxford and published in the journal Diabetologia. It has since become one of the most cited and clinically used tools in metabolic research and screening, with over 20,000 scientific papers referencing the methodology.
HOMA-IR is not a diagnostic test — it’s a quantitative screening tool. A high score doesn’t diagnose type 2 diabetes, but it is a powerful predictor of metabolic risk and guides lifestyle and therapeutic interventions.
How to Calculate HOMA-IR: The Formula Explained
HOMA-IR Formula:
HOMA-IR = (Fasting Insulin µIU/mL × Fasting Glucose mg/dL) ÷ 405
If your glucose is in mmol/L, convert first: mmol/L × 18.016 = mg/dL
Example: Glucose = 95 mg/dL, Insulin = 10 µIU/mL
HOMA-IR = (10 × 95) ÷ 405 = 950 ÷ 405 = 2.35 (borderline range)
The “405” constant in the denominator is derived from: 22.5 × 18 (where 22.5 is the original formula constant and 18 is the conversion factor from mmol/L to mg/dL). This formula assumes a simple mathematical relationship between insulin and glucose in the fasted state — when the body is in its baseline metabolic state.
Normal HOMA-IR Range: What Your Score Means
| HOMA-IR score | Interpretation | Clinical context |
|---|---|---|
| Below 1.0 | Optimal insulin sensitivity | Very low metabolic risk |
| 1.0–1.8 | Normal | Within healthy range; maintain lifestyle |
| 1.9–2.8 | Borderline | Early insulin resistance; lifestyle modification warranted |
| 2.9–4.9 | Elevated | Significant insulin resistance; medical evaluation recommended |
| 5.0+ | Very high | Marked insulin resistance; strongly associated with type 2 diabetes risk |
Note that reference ranges vary slightly between studies and populations. Some researchers set the borderline threshold at 2.5, others at 3.0. Asian populations may develop metabolic complications at lower HOMA-IR scores due to differences in body composition. Always interpret your score in context with your healthcare provider.
What Causes High Insulin Resistance?
- Excess body fat — particularly visceral fat (around abdominal organs) secretes inflammatory cytokines that directly impair insulin signalling
- Physical inactivity — skeletal muscle is the largest glucose disposal site; inactive muscle becomes less responsive to insulin
- High refined carbohydrate diet — chronically elevated blood glucose drives compensatory hyperinsulinaemia and eventual resistance
- Poor sleep — even one night of sleep deprivation can raise HOMA-IR by 25%
- Chronic stress — cortisol directly opposes insulin action and promotes visceral fat accumulation
- Genetics — family history of type 2 diabetes significantly increases susceptibility
- Ageing — muscle mass declines with age, reducing glucose disposal capacity
- Certain medications — corticosteroids, antipsychotics, and some blood pressure medications can worsen insulin resistance
Symptoms of Insulin Resistance
Insulin resistance often has no obvious symptoms in early stages, but common signs include:
- Persistent fatigue, especially after meals (postprandial drowsiness)
- Sugar and carbohydrate cravings, particularly in the afternoon
- Difficulty losing weight despite diet and exercise
- Abdominal weight gain (“belly fat”)
- Brain fog and difficulty concentrating
- Acanthosis nigricans — dark patches of skin at the neck, armpits, or groin
- Skin tags
- Elevated blood pressure
- Irregular menstrual cycles (in women with PCOS)
How to Reduce Insulin Resistance Naturally
Exercise — the most powerful intervention
Both aerobic exercise and resistance training improve insulin sensitivity. HIIT (high-intensity interval training) has been shown to reduce HOMA-IR by 25–40% in 8–12 weeks. Even a 30-minute walk after meals significantly lowers postprandial glucose.
Low-glycaemic, whole-food diet
Reducing refined carbohydrates, sugar, and ultra-processed foods lowers chronic insulin exposure. Mediterranean, low-carbohydrate, and whole-food plant-based diets all demonstrate significant HOMA-IR improvements in clinical trials.
Prioritise sleep quality
7–9 hours of quality sleep is metabolically essential. Poor sleep elevates cortisol and ghrelin, increases appetite for high-carbohydrate foods, and directly impairs insulin receptor sensitivity.
Time-restricted eating
Intermittent fasting (particularly 16:8 time-restricted eating) gives insulin levels extended recovery periods. Multiple studies show 12–18% HOMA-IR reduction with time-restricted eating alone, independent of caloric intake.
Stress management
Chronic cortisol elevation directly worsens insulin resistance. Meditation, yoga, adequate leisure time, and social connection all measurably improve cortisol profiles and metabolic markers.
Evidence-based supplements
Berberine, magnesium, inositol (particularly for PCOS), vitamin D, and omega-3 fatty acids have clinical evidence supporting improvements in insulin sensitivity. Always discuss with a healthcare provider before starting supplements.
Can Insulin Resistance Be Reversed?
Yes — in the large majority of cases, insulin resistance is reversible, particularly when addressed before type 2 diabetes develops. The key evidence:
- The DiRECT trial (2018) demonstrated that type 2 diabetes can be put into complete remission through structured dietary intervention — 86% of participants who lost 15+ kg achieved remission
- Exercise alone (without weight loss) improves insulin sensitivity within days by increasing GLUT4 transporter expression in muscle cells
- Low-carbohydrate diets reduce HOMA-IR within 2–4 weeks, often faster than any pharmaceutical intervention
- Visceral fat is highly responsive to diet and exercise — reduction in abdominal fat rapidly improves insulin signalling
The earlier insulin resistance is identified and addressed, the more reversible it is. This is why regular metabolic screening — including fasting insulin alongside fasting glucose — is valuable for anyone with metabolic risk factors.
Important Notes
What this calculator does and doesn’t cover
This tool applies the standard HOMA-IR formula to the numbers you enter. A few things worth understanding before relying on the results:
- HOMA-IR is a screening tool, not a diagnosis. It estimates insulin resistance from a single fasting blood draw, whereas the clinical gold standard (a euglycaemic-hyperinsulinaemic clamp) requires hospital equipment and isn’t used in routine screening.
- Accuracy depends entirely on a genuine fast. Eating, sugary drinks, or even black coffee with cream in the hours before the blood draw can shift both glucose and insulin readings and produce a misleading score.
- Reference thresholds vary between labs and studies. Some clinicians use 2.5 rather than 3.0 as the elevated threshold, and normal ranges can differ slightly by population and assay method. See the NIDDK’s overview of insulin resistance and prediabetes for how these markers fit into a broader diagnostic picture.
- HOMA-IR is less reliable for certain groups, including people with type 1 diabetes, anyone on insulin therapy, people with significant liver disease, and pregnant women, since the underlying model assumes typical fasting physiology.
- Rounding. The score is rounded to two decimal places for display.
- Not a diagnosis. An elevated result on this calculator does not mean you have diabetes or any other condition. See the CDC’s information on insulin resistance for further context, and discuss any concerning result with a healthcare provider who can interpret it alongside your full clinical picture.
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Your HOMA-IR score, risk category, and personalised metabolic insights are calculated above — free, instant, and based on the clinically validated HOMA-IR formula.
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