3 kn to mph — 3 knots in miles per hour
Exact 3 × 1.150779 = 3.452338
3 knots in other units
| Metres per second | 1.543333 | m/s |
|---|---|---|
| Kilometres per hour | 5.556 | km/h |
| Miles per hour | 3.452338 | mph |
| Feet per second | 5.06343 | ft/s |
kn to mph at a glance
| Knots | Miles per hour |
|---|---|
| 1 kn | 1.150779 mph |
| 2 kn | 2.301559 mph |
| 3 kn | 3.452338 mph |
| 5 kn | 5.753897 mph |
| 10 kn | 11.507794 mph |
| 20 kn | 23.015589 mph |
| 25 kn | 28.769486 mph |
| 50 kn | 57.538972 mph |
| 100 kn | 115.077945 mph |
| 250 kn | 287.694862 mph |
| 500 kn | 575.389724 mph |
| 1,000 kn | 1,150.78 mph |
How to convert knots to miles per hour
Multiply by 1.150779 — one knot is 1.150779 miles per hour. That factor is exact: it comes from the definition of the units rather than from a measurement, so it will not change and does not need rounding.
Working 3 × 1.150779 = 3.452338
In words: about three miles per hour.
Questions
How many miles per hour are in a knot?
One knot is 1.150779 miles per hour. This figure is exact — it comes from the definition of the unit, not a measurement.
What is 3 knots in miles per hour?
3 knots is 3.452338 miles per hour. The working is 3 × 1.150779 = 3.452338.
What is a knot?
One nautical mile per hour — and a nautical mile is one minute of latitude, fixed at exactly 1,852 metres. That is the whole point of it: a ship making 10 knots for six hours has covered one degree of latitude, which you can read straight off a chart without converting anything.
Why do sailors and pilots say "knots" and not "knots per hour"?
Because the "per hour" is already inside the word. A knot is a speed, not a distance, so "knots per hour" would be an acceleration. The name comes from the knotted rope once paid out behind a ship and counted against a sand glass.
What's the quick way to convert mph to km/h in my head?
Multiply by 1.6, or add 60%. For the other direction, take away a third and then a little more. Fifty mph is 80 km/h, 60 is 97, 70 is 113 — worth remembering if you drive across a border where the signs change.
Why isn't Mach on this page?
Because it is not a fixed unit. Mach 1 is the local speed of sound, which falls as air gets colder — around 1,235 km/h at sea level but closer to 1,062 km/h in the stratosphere where airliners cruise. A single conversion factor would be wrong nearly everywhere.