{"id":3190,"date":"2026-05-02T00:50:46","date_gmt":"2026-05-01T23:50:46","guid":{"rendered":"https:\/\/livingdiabetes.com\/hba1c-calculator\/"},"modified":"2026-05-02T00:50:46","modified_gmt":"2026-05-01T23:50:46","slug":"hba1c-calculator","status":"publish","type":"page","link":"https:\/\/livingdiabetes.com\/ur\/hba1c-calculator\/","title":{"rendered":"HbA1c to eAG Calculator \u2014 Convert HbA1c % or mmol\/mol to Average Glucose"},"content":{"rendered":"\n<p><strong>Convert HbA1c to estimated average glucose (eAG) \u2014 instantly, in either direction.<\/strong> Enter any of the four values below and the others update automatically. The conversion uses the formula validated by the ADAG (A1c-Derived Average Glucose) study, the same equation used by the American Diabetes Association.<\/p>\n\n\n\n<style>\n.ld-calc{max-width:720px;margin:1.5em 0;padding:1.5em;border:1px solid #d4dde5;border-radius:8px;background:#f8fafc;font-family:inherit}\n.ld-calc h3{margin-top:0;color:#1a4870;font-size:1.25em}\n.ld-row{display:flex;flex-wrap:wrap;gap:.75em;margin-bottom:.85em;align-items:center}\n.ld-row label{flex:1 1 230px;font-weight:600}\n.ld-row input,.ld-row select{flex:0 0 150px;padding:.5em .65em;font-size:1em;border:1px solid #b8c5d3;border-radius:4px;background:#fff}\n.ld-row input:focus,.ld-row select:focus{outline:none;border-color:#1a8cb6;box-shadow:0 0 0 3px rgba(26,140,182,.15)}\n.ld-result{margin-top:1.25em;padding:1em 1.25em;background:#e8f4f9;border-left:4px solid #1a8cb6;border-radius:4px;font-size:1.02em}\n.ld-result .big{font-size:1.4em;font-weight:700;color:#0d5a78;margin-bottom:.25em}\n.ld-result .interp{margin-top:.6em}\n.ld-btn{display:inline-block;background:#1a8cb6;color:#fff;border:none;padding:.65em 1.4em;border-radius:4px;font-size:1em;cursor:pointer;font-weight:600}\n.ld-btn:hover{background:#147099}\n.ld-note{margin-top:.75em;font-size:.88em;color:#555}\n.ld-disc{margin-top:1em;padding:.75em 1em;background:#fef9e7;border-left:3px solid #d4a017;border-radius:3px;font-size:.9em}\n@media (max-width:520px){.ld-row label{flex-basis:100%}.ld-row input,.ld-row select{flex-basis:100%}}\n<\/style>\n\n<div class=\"ld-calc\">\n  <h3>HbA1c \u2192 eAG Converter<\/h3>\n  <div class=\"ld-row\"><label for=\"ld-hba1c-pct\">HbA1c \u2014 DCCT (%)<\/label><input type=\"number\" id=\"ld-hba1c-pct\" step=\"0.1\" min=\"3\" max=\"20\" placeholder=\"e.g. 7.0\"><\/div>\n  <div class=\"ld-row\"><label for=\"ld-hba1c-mmol\">HbA1c \u2014 IFCC (mmol\/mol)<\/label><input type=\"number\" id=\"ld-hba1c-mmol\" step=\"1\" min=\"9\" max=\"200\" placeholder=\"e.g. 53\"><\/div>\n  <div class=\"ld-row\"><label for=\"ld-eag-mg\">Estimated avg glucose (mg\/dL)<\/label><input type=\"number\" id=\"ld-eag-mg\" step=\"1\" min=\"40\" max=\"500\" placeholder=\"e.g. 154\"><\/div>\n  <div class=\"ld-row\"><label for=\"ld-eag-mmol\">Estimated avg glucose (mmol\/L)<\/label><input type=\"number\" id=\"ld-eag-mmol\" step=\"0.1\" min=\"2\" max=\"30\" placeholder=\"e.g. 8.6\"><\/div>\n  <div class=\"ld-result\" id=\"ld-hba1c-result\" style=\"display:none\"><\/div>\n  <div class=\"ld-disc\">This calculator gives an <strong>average<\/strong>. Day-to-day glucose varies widely. Two people with the same HbA1c can have very different time-in-range. Use alongside, not instead of, your diabetes team&#8217;s advice.<\/div>\n<\/div>\n\n<script>\n(function(){\n  const pct=document.getElementById('ld-hba1c-pct'),mmol=document.getElementById('ld-hba1c-mmol'),mg=document.getElementById('ld-eag-mg'),mml=document.getElementById('ld-eag-mmol'),out=document.getElementById('ld-hba1c-result');\n  \/\/ ADA eAG: eAG (mg\/dL) = 28.7*A1c% - 46.7  | IFCC: NGSP% = 0.09148*IFCC + 2.152\n  const fromMmol=m=>0.09148*m+2.152,toMmol=p=>(p-2.152)\/0.09148,toMg=p=>28.7*p-46.7,toMml=mgv=>mgv\/18.018,fromMml=ml=>ml*18.018;\n  function show(p){\n    let c='',color='#0d5a78';\n    if(p<5.7){c='Within the non-diabetic range.';color='#2a7a3a'}\n    else if(p<6.5){c='Pre-diabetes \/ non-diabetic hyperglycaemia (NICE\/WHO range).';color='#c97f2a'}\n    else if(p<7.5){c='Diabetes \u2014 within a typical individualised NICE NG28 target for many adults.';color='#0d5a78'}\n    else if(p<8.5){c='Diabetes \u2014 above typical individual targets; clinicians often consider treatment intensification at this level.';color='#c44'}\n    else if(p<10){c='Diabetes \u2014 well above target; structured review with your diabetes team is recommended.';color='#a22'}\n    else{c='Very high \u2014 same-day or urgent contact with your diabetes team is advised.';color='#a22'}\n    out.innerHTML='<div class=\"big\" style=\"color:'+color+'\">HbA1c '+p.toFixed(1)+'% &nbsp;\/&nbsp; '+Math.round(toMmol(p))+' mmol\/mol<\/div>'+\n      '<div>eAG \u2248 '+Math.round(toMg(p))+' mg\/dL &nbsp;\/&nbsp; '+toMml(toMg(p)).toFixed(1)+' mmol\/L<\/div>'+\n      '<div class=\"interp\"><strong>Interpretation:<\/strong> '+c+'<\/div>';\n    out.style.display='block';\n  }\n  function update(src){\n    let p;\n    if(src===pct)p=parseFloat(pct.value);\n    else if(src===mmol)p=fromMmol(parseFloat(mmol.value));\n    else if(src===mg)p=(parseFloat(mg.value)+46.7)\/28.7;\n    else if(src===mml)p=(fromMml(parseFloat(mml.value))+46.7)\/28.7;\n    if(!isFinite(p)||p<3||p>20){out.style.display='none';return}\n    if(src!==pct)pct.value=p.toFixed(1);\n    if(src!==mmol)mmol.value=Math.round(toMmol(p));\n    if(src!==mg)mg.value=Math.round(toMg(p));\n    if(src!==mml)mml.value=toMml(toMg(p)).toFixed(1);\n    show(p);\n  }\n  [pct,mmol,mg,mml].forEach(el=>el.addEventListener('input',()=>update(el)));\n})();\n<\/script>\n\n\n\n<h2 class=\"wp-block-heading\">How the conversion works<\/h2>\n\n\n\n<p>HbA1c reflects your average blood glucose over roughly the previous 8\u201312 weeks (the lifespan of a red blood cell). The <strong>estimated average glucose (eAG)<\/strong> is that same average expressed in the units you&#8217;d see on a finger-prick or CGM \u2014 making the number easier to relate to day-to-day readings.<\/p>\n\n\n\n<p>Two formulas are used here:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>HbA1c% to eAG mg\/dL:<\/strong> eAG = 28.7 \u00d7 HbA1c \u2212 46.7 \u2014 derived from the ADAG study (Nathan et al., <em>Diabetes Care<\/em> 2008), used by the ADA.<\/li>\n<li><strong>HbA1c% (DCCT) to mmol\/mol (IFCC):<\/strong> mmol\/mol = (HbA1c% \u2212 2.152) \/ 0.09148 \u2014 the master equation used by the NGSP, NICE, and the IFCC.<\/li>\n<li><strong>mg\/dL to mmol\/L:<\/strong> divide by 18.018.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Reference ranges<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>HbA1c (%)<\/th><th>HbA1c (mmol\/mol)<\/th><th>eAG (mg\/dL)<\/th><th>eAG (mmol\/L)<\/th><th>Category<\/th><\/tr><\/thead><tbody>\n<tr><td>4.0<\/td><td>20<\/td><td>68<\/td><td>3.8<\/td><td>Normal<\/td><\/tr>\n<tr><td>5.0<\/td><td>31<\/td><td>97<\/td><td>5.4<\/td><td>Normal<\/td><\/tr>\n<tr><td>5.7<\/td><td>39<\/td><td>117<\/td><td>6.5<\/td><td>Pre-diabetes lower bound (ADA)<\/td><\/tr>\n<tr><td>6.0<\/td><td>42<\/td><td>126<\/td><td>7.0<\/td><td>Pre-diabetes (NICE non-diabetic hyperglycaemia)<\/td><\/tr>\n<tr><td>6.5<\/td><td>48<\/td><td>140<\/td><td>7.8<\/td><td>Diabetes diagnostic threshold<\/td><\/tr>\n<tr><td>7.0<\/td><td>53<\/td><td>154<\/td><td>8.6<\/td><td>Common adult target<\/td><\/tr>\n<tr><td>7.5<\/td><td>59<\/td><td>169<\/td><td>9.4<\/td><td>Above typical target<\/td><\/tr>\n<tr><td>8.0<\/td><td>64<\/td><td>183<\/td><td>10.2<\/td><td>Above target<\/td><\/tr>\n<tr><td>9.0<\/td><td>75<\/td><td>212<\/td><td>11.8<\/td><td>Significantly above target<\/td><\/tr>\n<tr><td>10.0<\/td><td>86<\/td><td>240<\/td><td>13.4<\/td><td>Well above target<\/td><\/tr>\n<\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">What HbA1c does <em>not<\/em> tell you<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Time in range.<\/strong> Two people with HbA1c 7.0% (53 mmol\/mol) can have completely different glucose patterns. CGM data is needed to see this.<\/li>\n<li><strong>Hypoglycaemia.<\/strong> HbA1c can look &#8220;good&#8221; because frequent lows are pulling the average down \u2014 a dangerous picture.<\/li>\n<li><strong>Recent changes.<\/strong> A diet or medication change in the past 2\u20133 weeks may not be fully reflected yet.<\/li>\n<li><strong>Conditions that distort HbA1c<\/strong> \u2014 pregnancy, anaemia, recent blood transfusion, haemoglobinopathies, chronic kidney disease, and some medications can all shift HbA1c away from what your true average glucose has been. Your team will know whether this applies to you.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Frequently asked questions<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">What&#8217;s the difference between HbA1c % and HbA1c mmol\/mol?<\/h3>\n\n\n\n<p>They&#8217;re the same measurement on two scales. The &#8220;%&#8221; (DCCT\/NGSP) scale is older and more familiar in the US. The mmol\/mol (IFCC) scale was internationally standardised and is the primary unit reported in the UK and most of Europe. Conversion is direct and exact.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Is eAG the same as my CGM average?<\/h3>\n\n\n\n<p>Close, but not identical. The eAG formula was derived from a mix of capillary, venous, and CGM data. Your CGM average (often called <strong>GMI \u2014 Glucose Management Indicator<\/strong>) is calculated from CGM data alone and may differ by up to 0.5% from your laboratory HbA1c. If they disagree, the lab HbA1c is usually the trusted value, but a persistent gap is worth discussing with your team.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What HbA1c should I aim for?<\/h3>\n\n\n\n<p>NICE NG28 recommends an individualised target \u2014 typically 48 mmol\/mol (6.5%) for adults managed by diet or a single non-hypoglycaemic medication, and 53 mmol\/mol (7.0%) for those on a medication carrying hypoglycaemia risk. Older adults, those with frailty, or those with recurrent hypoglycaemia have higher targets. Discuss your personal target with your diabetes team.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How often should HbA1c be checked?<\/h3>\n\n\n\n<p>Every 3\u20136 months until stable, then 6\u201312 monthly under NICE NG28 \u2014 and any time treatment changes substantially.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Can HbA1c be falsely low or high?<\/h3>\n\n\n\n<p>Yes. Conditions that shorten red-cell lifespan (haemolysis, recent transfusion, certain anaemias) can falsely <em>lower<\/em> HbA1c. Iron-deficiency anaemia, vitamin B12 deficiency, splenectomy, and some haemoglobin variants can falsely <em>raise<\/em> it. In all of these cases, fructosamine or CGM-derived GMI may be a better marker.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Related guides<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/livingdiabetes.com\/type-2-diabetes\/\">Type 2 Diabetes: Symptoms, Diagnosis, and Management<\/a><\/li>\n<li><a href=\"https:\/\/livingdiabetes.com\/diabetes-medications\/\">Diabetes Medications: a complete guide<\/a><\/li>\n<li><a href=\"https:\/\/livingdiabetes.com\/diabetes-complications\/\">Diabetes Complications: Heart, Kidney, Eye, and Foot Health<\/a><\/li>\n<\/ul>\n\n\n\n<p><em>References: Nathan DM et al. Translating the A1C assay into estimated average glucose values. Diabetes Care 2008;31:1473-78. NGSP master equation. NICE NG28 (Type 2 diabetes in adults). ADA Standards of Care 2026.<\/em><\/p>\n\n\n\n<p><em>Reviewed: May 2026.<\/em><\/p>\n\n","protected":false},"excerpt":{"rendered":"<p>Free HbA1c to estimated average glucose (eAG) calculator. Convert HbA1c % to mmol\/mol and to average glucose in mg\/dL or mmol\/L. Reference ranges, formula, and FAQ.<\/p>","protected":false},"author":4,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-3190","page","type-page","status-publish","hentry"],"rttpg_featured_image_url":null,"rttpg_author":{"display_name":"Claude SEO","author_link":"https:\/\/livingdiabetes.com\/ur\/author\/claude-seo\/"},"rttpg_comment":0,"rttpg_category":null,"rttpg_excerpt":"Free HbA1c to estimated average glucose (eAG) calculator. Convert HbA1c % to mmol\/mol and to average glucose in mg\/dL or mmol\/L. Reference ranges, formula, and FAQ.","_links":{"self":[{"href":"https:\/\/livingdiabetes.com\/ur\/wp-json\/wp\/v2\/pages\/3190","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/livingdiabetes.com\/ur\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/livingdiabetes.com\/ur\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/livingdiabetes.com\/ur\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/livingdiabetes.com\/ur\/wp-json\/wp\/v2\/comments?post=3190"}],"version-history":[{"count":0,"href":"https:\/\/livingdiabetes.com\/ur\/wp-json\/wp\/v2\/pages\/3190\/revisions"}],"wp:attachment":[{"href":"https:\/\/livingdiabetes.com\/ur\/wp-json\/wp\/v2\/media?parent=3190"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}