A necessary note. Values are the minimum candela transcribed directly from NFPA 72 §18.5.5 (Tables 18.5.5.7.1(a) and 18.5.5.7.1(b)). The wall-mount table only lists two configurations - one appliance per room, or four (one per wall), there is no listed "two on opposite walls" option, and four is marked not allowable below a minimum room size. Room sizes and ceiling heights round up to the next listed table size, the conservative direction. Select the nearest available candela rating at or above this minimum on the actual strobe being installed; not every exact value in the table is a standard product setting. This tool is a planning aid, not a substitute for a code review by a licensed design professional or your authority having jurisdiction.