HbA1c Converter

Convert HbA1c between NGSP % and IFCC mmol/mol, with estimated average glucose shown automatically in both mg/dL and mmol/L.

Last updated on: March 30, 2026

Convert HbA1c

Enter one HbA1c value only. The result will automatically show NGSP %, IFCC mmol/mol, eAG mg/dL, and eAG mmol/L.
Choose the unit of the value you entered. All major equivalent units will be displayed in the result automatically.

Clinical Significance

HbA1c may be reported in NGSP/DCCT percent units or in IFCC mmol/mol units, depending on the country, laboratory, or reporting standard.

Showing all equivalent outputs together makes interpretation easier and helps users compare HbA1c results with estimated average glucose in familiar daily glucose units.

Formula and Example

This calculator uses the official NGSP/IFCC master equation and the ADAG equation for estimated average glucose.

NGSP = (0.09148 × IFCC) + 2.152, IFCC = (10.93 × NGSP) - 23.50, and eAG (mg/dL) = (28.7 × NGSP) - 46.7.

Example: HbA1c 7.0% corresponds to about 53 mmol/mol, with an estimated average glucose of about 154 mg/dL or 8.6 mmol/L.

Reference Interpretation

Below Prediabetes Threshold: HbA1c below 5.7%. This is generally below the usual prediabetes threshold, though interpretation depends on the clinical context.
Prediabetes Range: HbA1c from 5.7% to 6.4%. This falls within the commonly used prediabetes range.
Diabetes Range: HbA1c 6.5% or higher. This falls within the commonly used diabetes diagnostic range, but diagnosis should follow established clinical criteria.

Clinical Notes

This converter is useful for reporting, interpretation, and communication, especially when users need to compare HbA1c across different unit systems.

  • NGSP % and IFCC mmol/mol are different unit systems for the same HbA1c concept.
  • Estimated average glucose is derived from HbA1c and is shown in both mg/dL and mmol/L for convenience.
  • Interpret HbA1c with caution in anemia, hemoglobin variants, pregnancy, recent transfusion, or altered red cell turnover.
  • This tool is intended for conversion and interpretation, not as a stand-alone diagnostic decision tool.

This page has been medically reviewed by Dr. Khoulah Attia – PharmD, Immunology Specialist.

Related Calculators

Remnant Cholesterol
GRACE Score
eAG from HbA1c Calculator
Albumin-to-Creatinine Ratio (ACR)
PESI Score Calculator
Pediatric NAFLD Fibrosis Index (PNFI)