ObjectivesThe reported prevalence of adenomyosis ranges widely due to different study populations, diagnostic tests and criteria. Categorizing the severity of disease may prove important. This study aims to develop a semi‐quantifiable sonographic method to grade the severity of adenomyosis and assess the feasibility and interobserver reliability of this method.MethodsCross‐sectional pilot study performed at a gynecology outpatient clinic, included 35 premenopausal women with adenomyosis, not taking hormonal medication. Diagnosis required ≥1 direct sonographic feature of adenomyosis. Two‐dimensional (2D) grayscale video clips and 3‐dimensional (3D) volumes of the uterus of the first 5 patients were evaluated using 6 offline methods to assess feasibility. Feasible methods were analyzed for interobserver (n = 3) reliability (Fleiss kappa or intraclass correlation) and compared with current ultrasound methods (Cohen's weighted kappa and Spearman's rank correlation). Current methods include real‐time estimation (mild/moderate/severe) and counting the individual sonographic features.Results“eXtended Imaging virtual organ computer‐aided analysis (XI VOCAL) counting” (counting affected slices of 20 parallel slices in the 3D volume), “Multiplanar and 3D rendering (MPR) estimation” (grading volume by eyeballing in multiplanar render mode), and “2D‐clip estimation” (grading volume in 2D‐clips) emerged as feasible methods. “XI VOCAL counting” and “2D‐clip estimation” demonstrated good interobserver reliability, whereas “MPR estimation” had poor reliability. Comparison with real‐time estimation showed moderate reliability with all methods. “XI VOCAL counting” and “MPR estimation” correlated positively with the number of sonographic features.Conclusion“XI VOCAL counting” demonstrated to be feasible with good interobserver reliability to assess the severity of adenomyosis in an objective, systematic, and semi‐quantifiable fashion and should be validated with large‐scale studies for future use. Future studies should also explore the association between sonographic severity and symptoms of adenomyosis.