HOMA-IR Calculator - Fasting Insulin Resistance Score

The HOMA-IR calculator turns a single fasting blood draw into a HOMA-IR score and a companion QUICKI index so you can read the same labs your clinician uses to flag insulin resistance, prediabetes, and metabolic syndrome risk.

• • Read a new fasting lab report: Someone with a fresh fasting insulin and glucose value enters both numbers and reads whether the HOMA-IR score sits in the optimal, borderline, or likely-resistance band, plus the matching QUICKI sensitivity score.
• • Track insulin resistance over time: A person on a lifestyle or medication plan for prediabetes logs the HOMA-IR score from each follow-up lab and watches it move with weight, fasting glucose, and A1c trends.
• • Screen for PCOS-related insulin resistance: A person with polycystic ovary syndrome uses the calculator against a stricter cutoff often used in reproductive endocrinology, then brings the score to a follow-up visit.
• • Prepare for a clinician conversation: A health-conscious user runs the calculator before an annual physical to know which questions to ask, which band they sit in, and whether the doctor should consider an oral glucose tolerance test.

Insulin resistance rarely produces symptoms in its early stages, so a numerical proxy such as HOMA-IR lets people act on a trend before prediabetes or type 2 diabetes develops. The calculator pairs the HOMA-IR result with a QUICKI index so the same two fasting values also describe sensitivity, the inverse of resistance.

The HOMA-IR result is informational, not a diagnosis, and it is only validated for samples drawn after at least eight hours of fasting. Bring the score to a clinician for any decision about medication, supplements, or diet change.

When the fasting report also has a Hemoglobin A1c, the Hemoglobin A1c Calculator translates the same lab into an estimated average glucose and an ADA classification band.

The HOMA-IR calculator multiplies fasting insulin by fasting glucose and divides by a constant that depends on the unit you choose, then computes the QUICKI index from the same pair of values.

• Fasting insulin: Insulin concentration in a fasting venous blood sample, reported in milliunits per liter (mU/L). The unit µIU/mL is identical to mU/L and is read the same way.
• Fasting glucose: Plasma glucose from the same fasting draw, entered in mg/dL (US labs) or mmol/L (SI labs). The unit selection switches the HOMA-IR denominator between 405 and 22.5.
• Glucose unit: Choose the unit printed on the lab report. The two denominators are equivalent because 1 mmol/L of glucose equals 18 mg/dL, so 22.5 multiplied by 18 equals 405.

The formula comes from Matthews and colleagues, who derived the HOMA model from physiologic studies of beta-cell function and insulin sensitivity. The original 1985 paper described the 22.5 mmol/L denominator, and the 405 mg/dL form is the same constant scaled by 18 to keep the index unitless regardless of the lab's glucose unit.

According to Matthews and the HOMA model developers, the index approximates the feedback loop between fasting glucose and fasting insulin in the liver, pancreas, and peripheral tissues. The HOMA-IR calculator applies that approximation in real time, so the result reflects the same equation your clinician would run by hand.

According to Matthews et al., Diabetologia 1985, HOMA-IR is calculated as fasting insulin (mU/L) multiplied by fasting glucose and divided by 22.5 (mmol/L) or 405 (mg/dL).

HOMA-IR is usually read alongside a fasting lipid panel, and the Cholesterol Ratio Calculator adds a total-to-HDL ratio from the same visit for context on cardiometabolic risk.

Four terms describe what the HOMA-IR score is doing behind the scenes, and they are worth knowing before you compare your number to online thresholds.

Think of HOMA-IR as a way to see the insulin-glucose tug-of-war before glucose starts to lose. If insulin and glucose are both normal, the index sits low. If insulin is creeping up while glucose still looks fine, the index is the first thing to move.

Once the HOMA-IR result is in hand, the Glycemic Index Calculator shows how individual foods move post-meal glucose, which is the lever most people use to bring fasting numbers down.

Enter the values from your most recent fasting blood draw, choose the unit printed on the lab report, and read the HOMA-IR score, QUICKI index, and band label in the results panel.

1. 1 Confirm the sample was fasting: Make sure the lab draw happened at least eight hours after your last food or drink other than water. A non-fasting sample will inflate the HOMA-IR score and is not valid for this calculator.
2. 2 Enter fasting insulin in mU/L: Type the lab-reported fasting insulin into the first field. If your report lists µIU/mL, treat it as identical to mU/L; the units are equivalent.
3. 3 Enter fasting glucose and pick the unit: Type the lab-reported fasting glucose into the second field, then choose mg/dL or mmol/L in the dropdown so the calculator uses the matching 405 or 22.5 denominator.
4. 4 Read the HOMA-IR score and QUICKI index: The results panel shows the HOMA-IR score with two decimals, the QUICKI index with three decimals, the glucose in mmol/L for cross-checking, and a band label.
5. 5 Compare against your prior readings: Pair the result with the Hemoglobin A1c Calculator to see whether trends over several months are improving, then share the trend at your next clinician visit.

A user with a US lab report of fasting insulin 12 mU/L and fasting glucose 105 mg/dL selects mg/dL, types 12 and 105, and the calculator returns HOMA-IR 3.11, QUICKI 0.323, and the label Likely insulin resistance, which is the cue to bring the report to a clinician.

Running HOMA-IR between clinical visits gives you a fast, repeatable read of metabolic health from values you may already have on a recent lab report.

• • Catch early insulin resistance: HOMA-IR moves before fasting glucose and A1c do, so the calculator can flag a trend toward prediabetes years before a formal diagnosis.
• • Track the same metric your clinician uses: Most primary care and endocrinology practices already quote HOMA-IR, so the calculator result matches the language in your visit notes.
• • Pair sensitivity and resistance in one view: QUICKI and HOMA-IR are computed from the same fasting pair, so the calculator shows both the resistance index and the sensitivity index without re-entering data.
• • Work with US or SI lab units: Switching the glucose unit between mg/dL and mmol/L keeps the math correct whether your lab report is from a US, UK, Canadian, or EU lab.
• • Prepare for a clinician conversation: The band label and the mmol/L cross-check give you a concrete number and a category to discuss, instead of bringing raw values without context.

Because the calculator is reproducible and free, you can run it on each new fasting lab report to see how the score moves with weight, sleep, exercise, and dietary changes. The QUICKI result is helpful when HOMA-IR is in the borderline range and a second index would change the read.

Insulin resistance usually travels with an abnormal lipid panel, so the LDL Calculator puts the Friedewald-style LDL estimate next to the HOMA-IR result at the same clinic visit.

The score is sensitive to the timing of the blood draw, the unit of glucose, and several non-disease factors that can move the index without reflecting true insulin resistance.

• • HOMA-IR is only validated for fasting venous samples. Post-meal capillary readings, CGM traces, and oral glucose tolerance test results should not be plugged into the formula.
• • The score is a screening estimate, not a stand-in for the hyperinsulinemic euglycemic clamp, which is the research reference method for measuring insulin resistance.

Cutoffs in the literature range from 1.4 in lean healthy young adults to 2.7 in PCOS populations, and most consumer-facing sources quote 2.0 or 2.5 as a practical threshold. The calculator displays four bands to reflect that range, and the citation below explains when HOMA-IR is a valid screening tool and when it should be set aside.

According to Katz et al., J Clin Endocrinol Metab 2000, the QUICKI index is calculated as 1 divided by the sum of the base-10 logarithms of fasting insulin (mU/L) and fasting glucose (mg/dL).

According to Wallace, Levy, and Matthews, Diabetes Care 2004, HOMA-IR is a valid screening tool for insulin resistance when the paired fasting insulin and glucose come from a single venous draw, and the result should be interpreted in the context of the population being studied.

Visceral adiposity is one of the strongest drivers of a high HOMA-IR score, and the Body Fat Calculator gives a percentage body-fat reading that pairs with the index for the same follow-up.