How fast in mph is 30 knots?

Answer 1

its ± 34.6 mph.
30 knots = 34.52 mph

If you meant nautical miles, then 30. Nautical Miles (per hour) and knots are basicly the same thing. the only difference is knots is based over seas soley due to raising and lowering tide levels (make it less accurate than physical distance) mile however is the distance of the ground. this is why most boats and all military have to recheck there voyage distance before setting sail as the tide may add or remove distance on them.

1 knot means 1 nautical mile per hour. The nautical mile used to be 6080 ft but it is now defined as exactly 1852 meters which makes it 6076 ft. The ratio to a normal mile is 1.1508, so 30 knots = 34.52 mph

Answer 2

30 knots = about 34.5 mph