<p>The majority of neighborhood calculators are restricted to one language. The limited availability of multilingual neighborhood calculators could pose challenges for conducting psycholinguistic research on low-resource languages. Therefore, this study introduced Jiwar, a database and calculator for neighborhood information across three levels (orthographic, phonological, and phonographic) across 40 languages. The database contains information for 24 linguistic and neighborhood measures, while the Python-based calculator allows users to compute more than 46 neighborhood measures for words and nonwords. This study further examined the Jiwar calculator’s instrument reliability and validity. Correlations with previous datasets across several languages suggested the strong reliability of two key Jiwar measures. Multiple-linear regression models revealed that a subset of Jiwar measures significantly predicted behavioral results in lexical decision and visual naming tasks, indicating the validity of the Jiwar calculator. Jiwar is an open-source, Python-based tool that is designed to expand to more languages and functions.</p>