HbA1C conversion chart

Glycated hemoglobin test, also known as HbA1C or A1C, is a blood test that shows you your average blood sugar level over the past 3-4 months. 

It is a routine test in people already diagnosed with diabetes to monitor their treatment and suggest the need to better control their diet or adjust medications. HbA1C test may be used also to diagnose diabetes in patients suspected to have it.

Table of Contents

 

What is HbA1C?

Glycated hemoglobin is a type of hemoglobin, the protein rich in iron found on red blood cells that allows to bind oxygen and transport it in the blood stream, that undergoes a chemical process known as glycosilation. The amount of hemoglobin that undergoes this transformation depends upon the amount of glucose available in the blood stream over the red blood cell lifespan, which is 120 days on average. For this reason, A1C is not affected by short term variation in blood sugar such as those induced by food intake, medications, stress or exercise.
Glycosilation is a non-easily reversible chemical process so a recent variation of the diet or change in the treatment plan won’t be reflected by HbA1C values until after several weeks due to the 4-months life span of RBCs.

 

HbA1C to mmol/L and mg/dL Conversion Chart

HbA1C to average blood glucose level conversion chart
HbA1C (%)mmol/Lmg/dL HbA1C (%)mmol/Lmg/dL HbA1C (%)mmol/Lmg/dL
4.03.8686.06.91258.010.2183
4.13.9716.17.11288.210.5189
4.24.1746.27.31318.410.8194
4.34.3776.37.41348.611.1200
4.44.4806.47.61378.811.4206
4.54.6826.57.81409.011.8212
4.64.7856.67.91439.212.0217
4.74.9886.78.11469.412.4223
4.85.1916.88.21489.612.7229
4.95.2946.98.41519.813.0235
5.05.4977.08.515410.013.3240
5.15.61007.18.715710.213.6246
5.25.71037.28.916010.413.9252
5.35.81057.39.016310.614.2258
5.46.01087.49.216610.814.6263
5.56.21117.59.416911.014.9269
5.66.31147.69.517111.515.7283
5.76.51177.79.717412.016.5298
5.86.71207.89.817712.517.3312
5.96.81237.910.018013.018.1326
  • Values in RED cells indicate poor diabetic control. (>9% A1C)
  • Values in YELLOW cells indicate fair diabetic control (8% to 9% A1C)
  • Values in GREEN-YELLOW cells indicate good diabetic control (<7% A1C)
  • Values in GREEN cells indicate expected results from non-diabetic individuals. (4% to 5.9% A1C)

Conversion from old units (NGSP or HbA1C %) to new units (IFCC or mmol/mol)

In the past 15 years, to report the results from the glycated hemoglobin test a new unit has been proposed and introduced . Some countries already adopted the new unit in their lab reports, while others still stick to the old unit or use both. 

While the results reported are the same, the numbers differ substantially and can create confusion. Here below you can find the conversion table from NGSP to IFCC units.

HbA1C % to mmol/mol conversion chart

NGSP (HbA1C %) to IFCC (mmol/mol) standard conversion chart for glycated hemoglobin test
HbA1C (%) - NGSPmmol/mol - IFCC HbA1C (%) - NGSPmmol/mol - IFCC HbA1C (%) - NGSPmmol/mol - IFCC
4.0206.0428.064
4.1216.1438.266
4.2226.2448.468
4.3236.3458.670
4.4256.4468.873
4.5266.5489.075
4.6276.6499.277
4.7286.7509.479
4.8296.8519.681
4.9306.9529.884
5.0317.05310.086
5.1327.15410.288
5.2337.25510.490
5.3347.35610.692
5.4367.45710.895
5.5377.55811.097
5.6387.66011.5102
5.7397.76112.0108
5.8407.86212.5113
5.9417.96313.0119
Sources