HOMA-β Beta Cell Function Calculator
Estimate HOMA1-%B from paired fasting glucose and insulin values using the original simplified equation—not the Oxford HOMA2 model.
Use the HOMA-β Beta Cell Function Calculator
Enter Fasting Lab Values
Use results from a blood draw taken after at least 8 hours of fasting.
Use the insulin unit reported by the lab; do not enter pmol/L here.
Formula (Matthews et al., 1985):
HOMA-β (%) = (20 × insulin µIU/mL) ÷ (glucose mmol/L − 3.5)
Enter your lab values and click
Calculate to see results.
Your Result
HOMA-β Beta-Cell Function
Model estimate only. There is no universal diagnostic low/normal/high cutoff for an individual result.
Glucose is close to the equation's 3.5 mmol/L boundary. Because the denominator approaches zero, HOMA1-%B can become extremely large and unstable; do not interpret this as a literal percentage of functioning cells.
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This result is for informational and research purposes only. Consult a qualified healthcare professional for clinical interpretation.
How to interpret HOMA1-%B safely
The original model uses 100% as a reference scale, not as a universal clinical target. Results depend strongly on the insulin assay and should normally be compared within the same population, laboratory and method. HOMA1-%B also does not adjust the estimate for insulin sensitivity.
This equation is not HOMA2. For nonlinear HOMA2-%B calculations, use the Oxford Diabetes Trials Unit HOMA2 calculator.
The companion HOMA1-IR value is shown only because both approximations use the same fasting pair. This page does not apply a universal HOMA1-IR or HOMA1-%B cutoff and does not infer compensation, diabetes, insulin resistance, or treatment need.
Primary references and privacy
Matthews et al. (1985) introduced HOMA from fasting plasma glucose and insulin. Wallace, Levy and Matthews (2004) describe the simplified HOMA1 equations, the 100% reference calibration, assay considerations and differences from HOMA2.
Privacy: the calculation runs locally in your browser. This tool does not upload or store the values you enter.
Summary
HOMA1-%B is a fasting-sample estimate of beta-cell function relative to the model reference value. This calculator uses fasting insulin in µIU/mL and glucose in mmol/L; glucose entered in mg/dL is converted automatically. It is useful for reproducing the simplified HOMA1 equation in research, but it is not a stand-alone diagnosis or a substitute for HOMA2 software or dynamic testing.
How it works
- Enter your fasting plasma glucose level and select the unit (mmol/L or mg/dL).
- Enter fasting serum insulin in µIU/mL (numerically equivalent to mIU/L).
- Click "Calculate" to apply HOMA1-%B = (20 × insulin) ÷ (glucose − 3.5) and companion HOMA1-IR = (glucose × insulin) ÷ 22.5.
- Review the converted inputs and visible formula substitution.
- Results are calculated entirely in your browser — no data is sent to any server.
Use cases
- Reproduce a published HOMA1-%B calculation from fasting laboratory values.
- Check glucose-unit conversion before calculating the index.
- Support clinical research on insulin secretion and pancreatic reserve.
- Interpret HOMA-β values obtained from academic or medical publications.
- Compare pre- and post-intervention beta-cell function in metabolic studies.
- Explain the difference between the simplified HOMA1-%B equation and HOMA2.