Case 1
- Glucose unit
- mg/dL
- Fasting glucose
- 100
- Fasting insulin
- 10µU/ml
2.47
Open with these valuesHOMA-IR Calculator
Change any value to update the result.
2.47
HOMA-IR index: 2.47Personal inputs stay on this device. Sharing sends the calculator page without these values.
Examples
Fasting glucose times fasting insulin, divided by 405 when glucose is in mg/dL and by 22.5 when it is in mmol/L. The two divisors differ by the factor 18 that separates the units, so picking the wrong one is an eighteen-fold error. The index estimates insulin resistance; it does not diagnose anything.
The numbers at a glance
Held fixed: Glucose unit mg/dL, Fasting glucose 100.0.
| Fasting insulin (µU/ml) | HOMA-IR index |
|---|---|
| 2.5 | 0.62 |
| 5.0 | 1.23 |
| 7.5 | 1.85 |
| 10.0Your value | 2.47 |
| 12.5 | 3.09 |
| 15.0 | 3.70 |
| 17.5 | 4.32 |
| 20.0 | 4.94 |
Worked examples
Case 2
- Glucose unit
- mg/dL
- Fasting glucose
- 90
- Fasting insulin
- 4µU/ml
0.89
Open with these valuesCase 3
- Glucose unit
- mmol/L
- Fasting glucose
- 5.5
- Fasting insulin
- 8µU/ml
1.96
Open with these valuesHow it's calculated
HOMA-IR = glucose × insulin ÷ 405 (mg/dL) or ÷ 22.5 (mmol/L)
- StepPick the unit your laboratory used for fasting glucose — mg/dL or mmol/L.Glucose unit=mg/dL·Fasting glucose=100
- StepEnter the fasting glucose and the fasting insulin from the same blood draw.Fasting glucose=100·Fasting insulin=10µU/ml
- ResultRead the HOMA1 approximation; the table contains arithmetic examples, not diagnostic bands.2.47
What this number means
This calculator uses the linear HOMA1 approximation: fasting glucose times fasting insulin, divided by the constant for the glucose unit. Use 405 for mg/dL and 22.5 for mmol/L, with insulin in µU/mL. The preset values, 100 mg/dL and 10 µU/mL, give 100 × 10 ÷ 405 = 2.47.
Glucose of 5.5 mmol/L with insulin of 8 µU/mL gives 5.5 × 8 ÷ 22.5 = 1.96. The two divisors differ by the glucose conversion factor of 18. Glucose and insulin must refer to the same fasting sample.
The reference table illustrates the arithmetic and does not classify results as normal or abnormal. This page supplies no diagnostic thresholds or treatment recommendations. HOMA1 is an approximation, and this calculation does not implement the separate HOMA2 computer model. Discuss the interpretation of your measurements with the clinician who requested them.
The divisor follows the glucose unit
It is 405 for mg/dL and 22.5 for mmol/L, with insulin in µU/mL either way. The two differ by the factor 18 that separates the units, so the wrong one is an eighteen-fold error.
Arithmetic examples, not diagnostic bands
The table shows calculated values only. This page does not classify your result or supply a diagnostic cut-off.
Both values, one fasting draw
Use glucose and insulin from the same fasting sample, with the units reported by your laboratory. Follow the preparation instructions supplied for your tests.
Commonly misread
MisconceptionMy HOMA-IR number establishes a diagnosis.
CorrectionThis is an arithmetic estimate from fasting measurements. The calculator does not establish a diagnosis or interpret your clinical circumstances.
MisconceptionMy glucose is in mmol/L, but I divided by 405 anyway.
CorrectionThe divisor belongs to the unit: 22.5 for mmol/L, 405 for mg/dL. Swapping them is an eighteen-fold error.
MisconceptionThis calculator gives the same output as HOMA2.
CorrectionIt uses the linear HOMA1 approximation. HOMA2 uses a separate computer model and is not implemented here.
Reference table
| Fasting values | HOMA-IR |
|---|---|
| 90 mg/dL · 4 µU/mL | 0.89 |
| 85 mg/dL · 6 µU/mL | 1.26 |
| 100 mg/dL · 10 µU/mL | 2.47 |
| 110 mg/dL · 15 µU/mL | 4.07 |
| 5.0 mmol/L · 6 µU/mL | 1.33 |
| 5.5 mmol/L · 8 µU/mL | 1.96 |
| 6.0 mmol/L · 12 µU/mL | 3.20 |
Questions
What is HOMA-IR?
HOMA-IR, the homeostatic model assessment of insulin resistance, estimates from a single fasting blood sample how strongly the body resists insulin. It combines fasting glucose and fasting insulin into one number. Higher values point to more resistance, lower ones to cells that respond well.
Which divisor applies, 405 or 22.5?
It depends on the glucose unit: 405 for mg/dL, 22.5 for mmol/L, with insulin in µU/mL either way. The ratio between them is 18, exactly the factor between the two glucose units, so both routes give the same index for the same blood sample. Using the wrong divisor is an eighteen-fold error.
What is a good HOMA-IR value?
This calculator does not supply normal ranges or diagnostic thresholds. Its reference table contains arithmetic examples only. Ask the clinician who requested the tests to interpret your measurements.
Do I have to be fasting?
The HOMA1 approximation uses fasting glucose and insulin from the same sample. Follow the preparation instructions provided for your laboratory tests.
Can HOMA-IR diagnose diabetes or prediabetes?
No. This page calculates the linear HOMA1 approximation and provides no diagnosis. A clinician must interpret your measurements and clinical circumstances.
Sources and last check
- HOMA1 — unit-specific arithmetic formulaFormula / method
Information, not medical advice.