HbA1c EstimatorHbA1c Estimator — Convert Blood Sugar to HbA1c

HbA1c (glycated haemoglobin, also written as A1c or glycohaemoglobin) is a blood test that reflects your average blood sugar level over the past 2–3 months. It measures the percentage of haemoglobin molecules in your red blood cells that have glucose attached to them. The higher your average blood sugar, the higher your HbA1c.

A normal HbA1c is below 5.7%. Pre-diabetes is diagnosed when HbA1c is between 5.7–6.4%. An HbA1c of 6.5% or higher on two separate occasions confirms a diabetes diagnosis. For people with diabetes, most guidelines recommend keeping HbA1c below 7.0%.

This tool uses the ADAG (A1c-Derived Average Glucose) formula, validated in a study of over 700 participants across multiple countries and endorsed by the ADA, EASD and IDF. The estimate is accurate within approximately ±0.5% of a lab result when based on a true 3-month average. However, factors like anaemia, kidney disease or haemoglobin variants can affect real HbA1c results — only a lab test gives a confirmed value.

For people with well-controlled diabetes: twice a year. If your treatment has changed or blood sugar is not well-controlled: every 3 months. For people with pre-diabetes or high risk: annually. Your doctor will advise the right frequency for your situation.

Fasting blood sugar is a snapshot — it shows your glucose level at one moment after not eating for 8 hours. HbA1c is a long-term average — it reflects how your blood sugar has been over the past 2–3 months. Both are used together for a full picture of your diabetes control. HbA1c is less affected by what you ate the previous day.

The most effective ways to lower HbA1c are: reducing refined carbohydrates and sugar, increasing physical activity (especially strength training and brisk walking), losing weight if overweight, following prescribed medications consistently, reducing stress, and improving sleep quality. Each 1% reduction in HbA1c significantly reduces the risk of diabetes complications.