Estimate SPL at the listening point
Sound Level Calculator
Apply free-field attenuation and compare with a selected alarm requirement.
Method context
BS 5839-1:2025 Clause 15
The implementation follows the current Swift calculator in the Fire Regs Pro project. It is an estimate for revision and preliminary checking.
Check before use: Confirm the current standard, project specification, manufacturer data, environmental derating and actual site measurements. A browser result is not a design certificate.