The EliteBook 850 G6 uses SHA-256 hashing with a unique salt per device . There is no calculator. Any online tool promising a "free master password" for the G6 is either:
If you currently have on the laptop, you might be able to set or clear the BIOS password using the HP BIOS Configuration Utility (BCU) without entering the BIOS. Download and install the HP BCU tool. Open Command Prompt as an Administrator. hp elitebook 850 g6 bios password reset