Coronary artery calcification (CAC) is a well-established cardiovascular disease (CVD) pathogenesis marker closely associated with dysregulated glucose and lipid metabolism. The present study investigated the relationship between the glycated hemoglobin A1c (HbA1c)/high-density lipoprotein cholesterol (HDL-C) ratio and CAC. A total of 1608 eligible participants were enrolled in the study. The HbA1c/HDL-C ratio was calculated by dividing HbA1c by HDL-C. LASSO regression, logistic regression, and receiver operating characteristic curve (ROC) analysis were performed to examine the relationship between the HbA1c/HDL-C ratio and CAC. The nomogram incorporating the HbA1c/HDL-C ratio was further established by multivariate logistic regression and evaluated. The HbA1c/HDL-C ratios in the CAC group were significantly higher than the control group [4.73 (4.01, 5.56) vs. 4.34 (3.67, 5.05), p < 0.001]. Subjects with an elevated HbA1c/HDL-C ratio (≥ 4.99) exhibited a higher prevalence of CAC [146/486 (30.04) vs. 200/1122 (17.83), p < 0.001]. Furthermore, an elevated HbA1c/HDL-C ratio was an independent effect factor for CAC [odds ratio, 1.135; 95% confidence interval (CI), 1.008-1.279; p = 0.037]. The area under the ROC curve of the HbA1c/HDL-C ratio was 0.630 (95% CI 0.596-0.663), and the model incorporating age, gender, body mass index, hypertension, diabetes mellitus, and the HbA1c/HDL-C ratio was 0.718 (95% CI 0.686-0.751). The constructed nomogram based on this model demonstrated favorable discrimination and clinical utility. In conclusion, the HbA1c/HDL-C ratio is closely associated with CAC and is an independent factor for CAC in asymptomatic adults without CVD.