Start with the service area your firm actually serves
The Census record identifies Sulphur city as a municipality in Calcasieu Parish and reports a 2020–2024 ACS 5-year population estimate of 20,775, with a margin of error of 30. That fact helps define a local audience, but it does not establish how many people need a lawyer, how many firms compete for attention, or where future clients search. For reputation work, the more important geographic question is whether your profile and review process accurately represent the places and legal services you serve. A firm may work in Sulphur while also accepting matters elsewhere in Calcasieu Parish or Louisiana; those relationships should be described accurately rather than implied from population data.
Recommended approach
Review the geographic wording on your Google Business Profile, website, intake materials, and review requests. Decide which service areas are legitimate for your practice and which locations should not be presented as offices or local presences. Use Sulphur and Calcasieu Parish only where they reflect your real operations and client service.
