Enter the fasting insulin level and fasting glucose level into the calculator to determine the insulin resistance index.
Medical disclaimer: This calculator is for educational use only and is not medical advice or a diagnosis. Do not change medications, insulin, diet, or exercise based solely on these results. Discuss results with a licensed clinician; diagnosis of diabetes/prediabetes requires validated testing (such as A1C, fasting plasma glucose, or an OGTT) and clinical evaluation. Seek urgent care for symptoms of severe high or low blood sugar.
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Insulin Resistance Index Formula
The following formulas are used to calculate the insulin resistance index (HOMA-IR) for given fasting insulin and glucose levels. The denominator depends on the glucose units used.
\text{HOMA-IR}=\frac{I \times G}{22.5}\quad (G\text{ in mmol/L})\\
\text{HOMA-IR}=\frac{I \times G}{405}\quad (G\text{ in mg/dL})Variables:
- IRI (HOMA-IR) is the insulin resistance index (unitless)
- I is the fasting insulin level (typically in µU/mL or mIU/L)
- G is the fasting glucose level (in mmol/L or mg/dL, matching the formula used)
To calculate the insulin resistance index (HOMA-IR), multiply the fasting insulin level by the fasting glucose level and then divide the result by 22.5 if glucose is in mmol/L, or by 405 if glucose is in mg/dL.
What is Insulin Resistance Index?
The insulin resistance index, often referred to as HOMA-IR (Homeostatic Model Assessment of Insulin Resistance), is a method used to estimate insulin resistance from fasting insulin and fasting glucose values. It is commonly used in research and sometimes in clinical settings as a surrogate index; interpretation can vary by population, lab methods, and clinical context, and it is not a stand-alone diagnostic test.
How to Calculate Insulin Resistance Index?
The following steps outline how to calculate the Insulin Resistance Index.
- First, determine the fasting insulin level (I).
- Next, determine the fasting glucose level (G).
- Next, calculate the insulin resistance index using HOMA-IR = (I × G) / 22.5 if glucose is in mmol/L (or HOMA-IR = (I × G) / 405 if glucose is in mg/dL).
- Finally, calculate the Insulin Resistance Index.
- After inserting the values and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Fasting insulin level (I) = 10 µU/mL
Fasting glucose level (G) = 90 mg/dL (≈ 5.0 mmol/L)
Insulin resistance index (HOMA-IR) = (10 × 90) / 405 = 2.22 (unitless)
