Notar520AC
Topic Author
Posts: 1517
Joined: Sat Jul 21, 2001 6:53 am

### Knots

Just a quick answer please- how many mph is a knot? Is there a conversion formula?
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apuneger
Posts: 2964
Joined: Fri Sep 08, 2000 2:43 pm

### RE: Knots

A knot is defined as follows (if I remember well):

If you travel one nautical mile per hour, your speed is exactly one knot.

Therefor, one knot is one nautical mile per hour.

I don't know how many statue miles that is, or how do you call that? However, I do know that it's about 1.5 kilometer, so one knot is more than one statue mile per hour.

Ivan

Plz correct me if I'm wrong
Ivan Coninx - Brussels Aviation Photography

777236ER
Posts: 12213
Joined: Sat Aug 18, 2001 7:10 am

### RE: Knots

Knot to MPH x1.1515

MPH to Knot x0.8684

Yeah, a knot is one nautical mile per hour
Your bone's got a little machine

777236ER
Posts: 12213
Joined: Sat Aug 18, 2001 7:10 am

### RE: Knots

Oh my god, i just realised i know that by heart. That's it, i'm committing myself now.
Your bone's got a little machine

Notar520AC
Topic Author
Posts: 1517
Joined: Sat Jul 21, 2001 6:53 am

### RE: Knots

Gracias.
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Jet-A gasguy
Posts: 259
Joined: Sun Dec 24, 2000 4:04 pm

### RE: Knots

Notar520AC,

hey buddy, how ya doin? Been flyin the NOTAR lately?

Jet-A gasguy

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timz
Posts: 6199
Joined: Fri Sep 17, 1999 7:43 am

### RE: Knots

In the past there have been slightly-different definitions of the nautical mile, but it's now supposed to be 1852 meters exactly, while the statute mile is 1609.344 meters exactly.

lapa_saab340
Posts: 396
Joined: Tue Aug 07, 2001 8:42 pm

### RE: Knots

Notar, if you want to roughly convert knots to mph and don't feel like using a calculator, you can do this:

Say your speed in knots is 160. Divide by ten (and get 16) and add it to your original to get 176mph. This gives you a rough estimate.
If you want a more exact answer, you do a little more math, just divide that 16 by 2, and add it as well.

So you have 160+16+8=184mph

The same applies if you want to convert mph to knots, except instead of adding to your mph speed, you subtract.

TAA_Airbus
Posts: 491
Joined: Mon Nov 01, 1999 4:34 pm

### RE: Knots

For those of you that dont know, which seems to be everyone otherwise it would of been said already, the nautical mile was derived from 1 minute of longitude on the equator.

Therefore 1' = 1nm

However, as far as conversions go, As I am unaware of the international standard for the radius of the earth at the equator, I cant work out what 1nm is in kms or St.miles

VirginFlyer
Posts: 4235
Joined: Sun Sep 10, 2000 12:27 pm

### RE: Knots

Um, I have always found these good:
Nautical->Statute (knot->mph): Divide by 8, multiply by 9
Statute->Nautical (mph->knot: Divide by 9, multiply by 8
"So powerful is the light of unity that it can illuminate the whole earth." - Bahá'u'lláh

timz
Posts: 6199
Joined: Fri Sep 17, 1999 7:43 am

### RE: Knots

The reason there have been various nautical miles in the past is the fact that the earth isn't spherical. WGS84 assumes the radius of the equator is 6378137 meters exactly, which makes a minute of longitude at the equator about 1855.325 meters. But a minute of latitude is 1842.905 meters at the equator and 1861.566 at the poles-- so presumably the now-official 1852-meter nautical mile is just a semi-arbitrary semi-average.

Boeing Nut
Posts: 5078
Joined: Fri Feb 23, 2001 2:42 am

### RE: Knots

One statue mile - 5,280 ft.

One nautical mile - 6,000 ft.
I'm not a real aeronautical engineer, I just play one on Airliners.net.

johnnybgoode
Posts: 2144
Joined: Wed Jan 03, 2001 8:47 pm

### RE: Knots

pretty simple:

say you´ve got 200 knots, take 2 times and then minus 10%.
so that´s 200x2=400 400-40=360

200kts= ~360mph

rgds
daniel
If only pure sweetness was offered, why's this bitter taste left in my mouth.

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