Converts HbA1c values between the JDS and NGSP notations.
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Calculation basis and official references
Reviewed on:
This calculator is not a diagnosis, treatment plan, or prescription. Please consult a qualified clinician about your medical decisions.
Formula basis
NGSP value (%) = 1.02 x JDS value (%) + 0.25. Conversely, JDS value (%) = 0.980 x NGSP value (%) - 0.245. Depending on the selected input scale, the entered value is shown as-is on one side and the converted value is shown on the other.
Calculation method
Converts HbA1c values between the JDS and NGSP notations using the conversion formula established by the Japan Diabetes Society in 2012.
Exclusions and checks required
This conversion formula is a statistical approximation defined by the Japan Diabetes Society; it may differ slightly from a directly measured value for a given specimen or instrument.
In some institutional contexts (such as specific health checkups), only the JDS notation may still be used depending on the period; this calculator only converts between notations and does not determine which notation should be used in a given context.
Example input:：Example: converting an NGSP value of 6.0% to a JDS value
value
6
scale
NGSP
The converted value only aligns two notations of the same measurement; it does not by itself represent a diagnostic threshold for diabetes.
Who is this calculator for? HbA1c JDS-NGSP Conversion
Converts HbA1c values between the JDS and NGSP notations.
What values should I enter?
Applies to: Lab values
How should I interpret this estimate?
Converts HbA1c values between the JDS and NGSP notations using the conversion formula established by the Japan Diabetes Society in 2012.
How to use
Enter your input values and press Calculate.
Review the result and compare it with expected context.
NGSP value (%) = 1.02 x JDS value (%) + 0.25. Conversely, JDS value (%) = 0.980 x NGSP value (%) - 0.245. Depending on the selected input scale, the entered value is shown as-is on one side and the converted value is shown on the other.