HOMA-B Calculator (Beta-Cell Function)
Estimate pancreatic beta-cell function using fasting glucose and fasting insulin values.
Formula used (HOMA1): HOMA-B (%) = (20 × fasting insulin in µU/mL) / (fasting glucose in mmol/L − 3.5)
What Is HOMA-B?
HOMA-B is a mathematical estimate of pancreatic beta-cell function. Beta cells are the insulin-producing cells in the pancreas. Clinicians and researchers often use HOMA-B together with HOMA-IR to understand glucose metabolism and early signs of insulin resistance or impaired insulin secretion.
This calculator uses the classic HOMA1 model, which is commonly applied in educational and research settings when fasting labs are available.
How the HOMA-B Calculator Works
Inputs You Need
- Fasting glucose (either mg/dL or mmol/L)
- Fasting insulin (µU/mL)
Computation Steps
- If glucose is entered in mg/dL, it is converted to mmol/L by dividing by 18.
- The formula is then applied: (20 × insulin) / (glucose mmol/L − 3.5).
- The calculator displays your HOMA-B estimate and a general interpretation.
How to Interpret Your Result
There is no single universal cutoff for every person or population. Interpretation depends on age, body composition, ethnicity, medications, and clinical context. As a broad educational guide:
- Below 50%: May suggest lower beta-cell function.
- 50%–100%: Often considered a moderate range in many contexts.
- 100%–200%: May indicate preserved or compensatory insulin secretion.
- Above 200%: Can be seen with high insulin output, sometimes in insulin resistance states.
These ranges are not diagnostic by themselves. A healthcare professional should interpret results with your full lab panel and medical history.
Important Limitations
It Is an Estimate, Not a Diagnosis
HOMA-B is a surrogate marker derived from fasting values, not a direct measurement of beta-cell performance under all physiological conditions.
Fasting Quality Matters
Recent food intake, stress, illness, sleep loss, and some medications can change glucose and insulin levels, affecting your calculated value.
Model Constraints
The equation requires fasting glucose (in mmol/L) to be greater than 3.5. Values near or below that threshold can make the formula unstable or invalid.
When This Tool Is Most Useful
- Tracking trends over time with repeat fasting labs
- Discussing insulin secretion patterns with your clinician
- Comparing lifestyle intervention periods (diet, activity, weight change)
- Educational understanding of metabolic health metrics
Frequently Asked Questions
Can I use random (non-fasting) values?
No. HOMA-B is designed for fasting measurements. Non-fasting values can significantly distort results.
Is HOMA-B the same as HOMA2-B?
No. This page uses the HOMA1 equation. HOMA2 uses a nonlinear computer model and can produce different values.
Should I rely on this number alone?
No. Consider HbA1c, fasting glucose trends, C-peptide (when indicated), lipid profile, anthropometrics, and clinical symptoms alongside HOMA-B.
Medical Disclaimer
This calculator is for informational and educational purposes only. It is not medical advice and does not replace professional diagnosis or treatment.