HOMA-IR Calculator

You got your bloodwork back. Fasting glucose: 94 mg/dL. Your doctor says it's normal. And technically, it is.

But that number hides something. It doesn't tell you how much insulin your body needed to keep your glucose at 94. Was it a comfortable 5 μU/mL? Or was your pancreas grinding out 18 μU/mL just to hold the line? Those two scenarios look identical on a standard lab report. Metabolically, they're worlds apart.

That's the blind spot HOMA-IR exposes. This calculator takes your fasting glucose and fasting insulin — two simple lab values — and reveals whether your body is quietly losing its ability to use insulin effectively. It catches insulin resistance years before your blood sugar ever crosses into the prediabetic range, when it's still easy to reverse.

You'll get two scores: HOMA-IR (measuring resistance) and QUICKI (measuring sensitivity). Together, they give you a clearer metabolic picture than either number alone.

HOMA-IR stands for Homeostatic Model Assessment of Insulin Resistance. It's a formula that uses your fasting glucose and fasting insulin to answer one question: how hard is your pancreas working to keep blood sugar under control?

Here's the logic. Insulin is the key that unlocks your cells to let glucose in. In a healthy body, a small amount of insulin does the job. But when cells start ignoring insulin's signal — insulin resistance — the pancreas compensates by producing more. Blood sugar stays "normal" for years while insulin climbs higher and higher behind the scenes. Eventually the pancreas can't keep up, glucose rises, and suddenly you have prediabetes.

HOMA-IR catches you in that hidden middle phase. The formula:

HOMA-IR = (Fasting Glucose in mg/dL x Fasting Insulin in μU/mL) / 405

If your lab reports glucose in mmol/L, it's:

HOMA-IR = (Fasting Glucose in mmol/L x Fasting Insulin in μU/mL) / 22.5

Lower is better. A metabolically healthy person might score 0.5 to 1.0. Someone whose pancreas is working overtime to compensate for resistant cells will score 3, 4, or higher.

For reference, healthy adults in population studies typically score between 0.5 and 1.4. Once you cross 2.5, you're in the top quartile for insulin resistance. Above 4.0 is commonly seen in people with established type 2 diabetes.

Here's something worth knowing: most routine bloodwork doesn't include fasting insulin. You get fasting glucose. Maybe an A1C. But not the one number that would let you calculate HOMA-IR.

That means millions of people get told their blood sugar is "normal" while their insulin levels are silently climbing. Their fasting glucose might sit at a comfortable 95 mg/dL for a decade while their fasting insulin creeps from 6 to 12 to 20 — and nobody notices because nobody ordered the test.

If you want your HOMA-IR calculated, you need to specifically ask your doctor for a fasting insulin test alongside your glucose. Some providers order it routinely for patients with risk factors (family history of diabetes, PCOS, metabolic syndrome, obesity). Others won't think to run it unless you ask. So ask.

This calculator also gives you a QUICKI score — the Quantitative Insulin Sensitivity Check Index. It uses the exact same two lab values but measures the opposite side: sensitivity instead of resistance.

QUICKI = 1 / (log₁₀(Fasting Insulin) + log₁₀(Fasting Glucose in mg/dL))

Why run both? Because borderline cases can be tricky. If your HOMA-IR says 1.8 (technically early resistance) but your QUICKI says 0.36 (possible resistance), both are pointing the same way — and that agreement gives you more confidence in the picture. If they diverge, that nuance is worth discussing with your provider.

Think of it like getting two doctors' opinions from a single blood draw.

HOMA-IR isn't the only way to assess metabolic health. Here's how it stacks up:

This is why HOMA-IR is so valuable for early detection. Fasting glucose and A1C can look completely normal for years while insulin resistance builds underneath. HOMA-IR spots the problem during that hidden window — when lifestyle changes are most effective and least difficult.

1. Enter your fasting glucose. This is your blood sugar from a test taken after 8–12 hours of fasting. You'll find it on any standard metabolic panel.
2. Select your glucose unit. Choose mg/dL (standard in the U.S.) or mmol/L (used in Europe, Canada, and Australia).
3. Enter your fasting insulin. This is measured in mU/L (also written as μU/mL — they're the same unit). You may need to specifically request this test, as it's not always included in routine bloodwork.
4. Read your results. You'll instantly see your HOMA-IR score, QUICKI score, and what each means in plain language.

Critical: both values must come from the same blood draw, taken fasted. Glucose from one visit and insulin from another will produce meaningless results.

Maria's annual bloodwork showed fasting glucose of 92 mg/dL. Normal range. Her doctor didn't mention it twice. But Maria had also requested a fasting insulin, which came back at 14 μU/mL.

HOMA-IR = (92 x 14) / 405 = 3.18 — severe insulin resistance.

Her glucose looked fine because her pancreas was working triple shifts to keep it there. Without that insulin test, she'd have walked out of her appointment thinking everything was great. Instead, she caught the problem early — with time to reverse it through diet and exercise rather than medication.

This is the most common scenario we see. "Normal" glucose masking significant insulin resistance.

James was diagnosed with prediabetes. Starting labs: fasting glucose 110 mg/dL, fasting insulin 18 μU/mL.

Starting HOMA-IR = 4.89 — severe resistance.

His doctor gave him the standard talk: lose weight, eat better, exercise. James got specific. He walked 30 minutes every morning before breakfast. He replaced his nightly pasta with grilled chicken and vegetables three days a week. He stopped drinking juice. Over 16 weeks, he lost 12 pounds.

New labs: glucose 94 mg/dL, insulin 8 μU/mL. New HOMA-IR = 1.86.

That's a 62% reduction. He went from severe insulin resistance to early — not perfect, but a metabolic transformation. His doctor pushed back the metformin conversation. James retests every three months to keep the trajectory going.

Priya had been dealing with irregular periods and stubborn weight gain for years before getting a PCOS diagnosis. Her endocrinologist ran the right labs: glucose 88 mg/dL, insulin 20 μU/mL.

HOMA-IR = 4.35 — severe resistance, despite glucose most people would call "good."

This score changed everything. Her provider had been considering lifestyle-only treatment, but a HOMA-IR above 4.0 justified starting metformin alongside dietary changes. Research shows this combination is particularly effective for insulin-resistant PCOS — and Priya's HOMA-IR made the case clearly.

David exercises four times a week and eats mostly whole foods. No health concerns. He requested fasting insulin out of curiosity.

HOMA-IR = (82 x 4) / 405 = 0.81 — optimal.

No action needed. But now David has a number to compare against in five years, ten years, twenty. If it starts creeping up from 0.81 to 1.4 to 2.0, he'll catch the trend long before it becomes a problem. That's the value of a baseline — even when the news is good.

Your score doesn't exist in a vacuum. Here's what research shows for different populations:

These are general ranges from clinical studies — individual variation exists. But they give you context for where your number falls relative to different metabolic profiles.

HOMA-IR is only as reliable as the labs you put into it. Here are the errors that skew results most often:

Not fasting long enough. You need 8–12 hours with nothing but water. Coffee — even black — can stimulate insulin release. A midnight snack followed by a 7 AM draw? That's only 7 hours. Not enough.

Testing during illness or acute stress. Got the flu last week? Pulled an all-nighter? Going through a major life event? Cortisol and other stress hormones spike both glucose and insulin regardless of your actual insulin resistance. Wait until things settle before testing.

Using values from different blood draws. Your fasting glucose from January and fasting insulin from March can't be combined. Both must come from the same draw, on the same day, in the same fasted state. Glucose and insulin fluctuate daily.

Comparing results between labs. Insulin assays aren't perfectly standardized. If you're tracking HOMA-IR over time — which you should be — use the same lab for every test.

Ignoring medication effects. Metformin, sulfonylureas, berberine, GLP-1 agonists, and injected insulin all change your numbers directly. Your HOMA-IR on these medications reflects your treated state, not your underlying resistance level. That's not a flaw — it's just something to keep in mind.

Generic advice to "eat better and exercise" isn't very helpful. Here's what actually moves the needle on insulin resistance specifically:

Exercise — and the type matters. Both cardio and strength training improve insulin sensitivity, but through different pathways. Aerobic exercise (walking, cycling, swimming) improves how your muscles absorb glucose during activity. Resistance training (weights, bodyweight exercises) increases muscle mass, which acts as a larger "glucose sink" 24/7 — even when you're sitting on the couch. Combining both gives the biggest HOMA-IR reduction. Studies show measurable improvement within 4–8 weeks of consistent activity. Even a single bout of moderate exercise improves insulin sensitivity for 24–48 hours afterward.

Lose the specific fat that matters. Total weight loss helps, but visceral fat — the fat packed around your liver, pancreas, and intestines — is the primary driver of insulin resistance. You can't spot-reduce it, but it tends to be the first fat lost with consistent exercise and dietary changes. Losing just 5–7% of body weight (10–14 pounds for someone at 200) can reduce HOMA-IR by 30–40%.

Fix your sleep before you fix your diet. This surprises people. One week of sleeping 5 hours instead of 8 increases insulin resistance by 25–30% — even in young, healthy adults. Poor sleep disrupts cortisol rhythms, increases appetite for high-carb foods, and directly impairs insulin signaling. If you're sleeping under 7 hours consistently, that might be the single highest-leverage change you can make.

Lower your glycemic load, not just "carbs." You don't need to go low-carb to improve HOMA-IR. You need to reduce how hard your pancreas has to work after meals. That means swapping refined carbs (white bread, juice, sugary cereals) for fiber-rich whole foods (vegetables, legumes, whole grains), and pairing carbs with protein or fat to slow absorption. A sweet potato with butter and chicken creates a much gentler insulin response than the same calories from a bagel.

Address chronic stress directly. Cortisol is an insulin antagonist — it increases glucose production and blocks insulin signaling simultaneously. Chronic psychological stress keeps cortisol elevated and keeps HOMA-IR elevated right along with it. Whatever lowers your stress reliably — walking, meditation, therapy, setting boundaries at work — has a measurable metabolic payoff.

Ask your doctor for a fasting insulin test if you:

• Have prediabetes or a family history of type 2 diabetes
• Have PCOS or are being evaluated for it
• Notice unexplained weight gain, especially around your midsection
• Have been diagnosed with metabolic syndrome, fatty liver, or high triglycerides
• Simply want a deeper metabolic picture than fasting glucose alone provides

How often to retest:

• Normal HOMA-IR (below 1.9): Annually is reasonable for ongoing monitoring.
• Actively improving (lifestyle changes in progress): Every 3–4 months. This gives your body enough time to respond and gives you a clear trend line.
• On medication (metformin, GLP-1 agonists, etc.): Follow your doctor's schedule, typically every 3–6 months.

A single HOMA-IR is a snapshot. Trends over time tell the real story. Track it.

HOMA-IR is a screening tool, not a diagnosis. It estimates insulin resistance through a mathematical model — it doesn't directly measure what's happening at the cellular level. The gold standard for that is the euglycemic-hyperinsulinemic clamp, a research procedure that's far too invasive and expensive for routine use.

What HOMA-IR gives you is a practical, validated approximation that correlates strongly with clamp studies and has been used in thousands of clinical research papers since 1985. It works best as one piece of your metabolic picture — alongside A1C, lipid panels, waist circumference, and blood pressure — rather than a standalone verdict.

Your results deserve a conversation with a healthcare provider who knows your full history. Bring the numbers. Ask the questions. That's what this tool is for.