"Result should be 21.55729613 Kts "
So then, not only is it a wee bit BEEGER than a Tornado, but also a wee bit SLOWER ! (Don`t hit me, Mr. Roberts.)

Please tell me there`s only one kind of mile. I can deal with the fact that many countries have "dollars" and they are all worth surprisingly different amounts, from the US$ to the Zimbabwe $ (which has no value, really, not even in Zimbabwe), but I`m hoping against the odds that when someone mentions "miles" they are referring to the same thing. I get all nervous when someone says "statute miles", is that like miles wearing traffic police uniforms ?

Last I knew, one mile = 1,609km = 0,868 knots, or 1knot = 1.1516469857054070851460534493474 mph.

Answer to Mary : If you know the conversion factors, you can sail a race in miles or km, convert the distance to nautical miles, calculate nautical miles per hour, and you should get your average speed in knots.

Steve