How fast is 345 fps in mph?

330 fps is 330 feet per second. Mph is miles per hour, so convert your units.

330 ft * 1 mi / 5280 ft = 0.0625 mi

1 sec * 1 hr / 3600 hr = 0.000278 hr

0.0625 mi / 0.000278 hr = 225 mi / hr