As multi/plurilingual research advances understandings of plurilingual speakers' fluid language use, particularly in multilingual settings, new research methods and pedagogical orientations that address this complex phenomenon are needed. The present study considered the development, reliability, and validity of the Plurilingual and Pluricultural Competence (PPC) scale. Informed by sociolinguistics theories in educational linguistics, including plurilingualism and translanguaging, the PPC scale had its content validated by researchers, language teachers and learners. It was then implemented with 379 plurilingual speakers in two multilingual cities in Canada: 129 in Toronto and 250 in Montréal. Exploratory factor analysis examined the factors in the scale and whether PPC referred to language and culture as separate dimensions or, as theoretically suggested, a unidimensional construct. Results reveal PPC as one construct, suggesting that language and culture are interrelated. With 22 items on a 4-point Likert scale, the PPC scale is a new instrument that can be used in future multi/plurilingual research and pedagogy. Its significance lies in that the scale can gather overall trends among plurilinguals' PPC levels, which can have implications for language education, curriculum and policy. Recommendations for future use are discussed.