{"id":"cholesterol-hdl-ratio","name":"Total Cholesterol / HDL Ratio","shortName":"Chol/HDL Ratio","aliases":["Chol/HDLC Ratio","Cholesterol/HDL Ratio","T. Chol/HDL Ratio","TC/HDL Ratio","Castelli Risk Index I","CHOL/HDL RATIO","TC/HDL","Cholesterol ratio","Castelli index I","Total Cholesterol/HDL Ratio","Total Cholesterol to HDL Ratio","Cholesterol/HDL-C Ratio","Chol/HDL Ratio","Total:HDL Ratio","Total/HDL Cholesterol Ratio","TC:HDL ratio","Cholesterol Total/HDL Ratio","Total Cholesterol:HDL Ratio","Cholesterol/HDL cholesterol ratio, calculated"],"abbreviations":["TC/HDL","TC:HDL","Chol/HDL"],"loinc":[{"code":"9830-1","primary":true},{"code":"32309-7","primary":false}],"specimen":"calculated","units":[{"ucum":"{ratio}","display":"ratio"}],"referenceRanges":[{"population":"Adults","low":null,"high":4.9,"unit":"{ratio}","unitDisplay":"ratio","note":"Quest lists the ratio as below 5.0 for both sexes, with no age split. The upper limit here is 4.9 because the ratio is reported to one decimal place. This is a lab cutoff and not a guideline category: current guidelines do not use lipid ratios to guide treatment, and neither ATP III nor the 2018 ACC/AHA cholesterol guideline sets a ratio target. Labcorp reports the ratio on its lipid panel with ratio (test 221010) but its test directory page prints no interval, and other labs use other cutoffs, so check the range printed on your own report.","sources":[{"title":"Lipid Panel with Ratios, Quest Diagnostics (reference ranges as listed by Fullscript)","url":"https://us.fullscript.com/labs/quest/lipid-panel-with-ratios","publisher":"Quest Diagnostics (via Fullscript)"},{"title":"Lipid Profile Testing and Interpretation (summarizes the 2026 ACC/AHA Dyslipidemia Guideline)","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC13339843/","publisher":"Circulation (Nguyen, Ahmad, Navar)","year":2026},{"title":"Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III): Executive Summary","url":"https://www.nhlbi.nih.gov/files/docs/guidelines/atp3xsum.pdf","publisher":"NHLBI / National Institutes of Health","year":2001},{"title":"2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol: Executive Summary","url":"https://pmc.ncbi.nlm.nih.gov/articles/PMC7403606/","publisher":"ACC/AHA Task Force on Clinical Practice Guidelines","year":2019},{"title":"Lipid Panel With Total Cholesterol:HDL Ratio (test 221010)","url":"https://www.labcorp.com/tests/221010/lipid-panel-with-total-cholesterol-hdl-ratio","publisher":"Labcorp"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"Your total cholesterol divided by your HDL (\"good\") cholesterol. Some labs print it as a single number that sums up your cholesterol balance.","url":"https://bloodtesttracker.com/markers/cholesterol-hdl-ratio","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}