Fructosamine Calculator

Estimate HbA1c and average glucose from fructosamine for a practical short-term view of glycemic exposure.

Last updated on: March 30, 2026

Calculate from Fructosamine

µmol/L
Enter fructosamine in µmol/L. The result will automatically show estimated HbA1c and estimated average glucose.

Clinical Significance

Fructosamine reflects average glycemic exposure over approximately the previous 2 to 3 weeks, making it useful when a shorter-term view is needed.

It can be helpful when HbA1c is less reliable or when recent treatment changes need to be assessed more quickly than HbA1c allows.

Formula and Example

This calculator uses an approximate conversion formula: Estimated HbA1c (%) = 0.017 × Fructosamine (µmol/L) + 1.61.

It then estimates average glucose from the estimated HbA1c using the ADAG relationship for practical interpretation.

Example: fructosamine 285 µmol/L gives an estimated HbA1c of about 6.5%, with an estimated average glucose of about 140 mg/dL or 7.8 mmol/L.

Reference Interpretation

Estimated HbA1c Below Prediabetes Threshold: Estimated HbA1c below 5.7%. This is generally below the usual prediabetes threshold, though interpretation depends on the clinical setting.
Estimated HbA1c in Prediabetes Range: Estimated HbA1c from 5.7% to 6.4%. This falls within the commonly used prediabetes range.
Estimated HbA1c in Diabetes Range: Estimated HbA1c 6.5% or higher. This falls within the commonly used diabetes range, but diagnosis should not rely on this estimate alone.

Clinical Notes

Fructosamine is best viewed as a short-term glycemic marker. Estimated HbA1c from fructosamine is useful for interpretation but should not be treated as an exact laboratory equivalent in every patient.

  • Fructosamine generally reflects glycemia over about 2 to 3 weeks.
  • It may be useful when HbA1c is less informative or when therapy changed recently.
  • Estimated HbA1c from fructosamine is approximate and depends on the conversion model used.
  • Interpret together with glucose readings, treatment changes, protein status, and the overall clinical context.

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