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.