20 kn to mph
- Knots (kn)
- 20 kn
- Miles per hour
- 23.0155889605 mph
Checked against: Exact-fraction computation from the legal unit definitions
Knots to miles per hour converter
Convert knots to miles per hour (knots to mph) with the exact factor, a conversion chart and worked steps.
By AdminDrafted with AI writing toolsUpdated Checked examples: 3
Miles per hour
mph
Miles per hour: 23.0155889605 mph
- Conversion
- 20 kn = 23.0155889605 mph
- 1 mph in knots
- 0.8689762419kn
20 kn is about 23.0155889605 mph. In the other direction, 1 mph ≈ 0.86897624 kn.
Knots to miles per hour
Knots to mph chart
| Knots | Miles per hour |
|---|---|
| 1 | 1.1508 |
| 5 | 5.7539 |
| 10 | 11.5078 |
| 15 | 17.2617 |
| 20 | 23.0156 |
| 25 | 28.7695 |
| 30 | 34.5234 |
| 40 | 46.0312 |
| 50 | 57.539 |
| 100 | 115.0779 |
How it's calculated S
Conversion factor
Rounded here for display; the calculation uses 50 significant digits.
Multiply
About the knots to miles per hour converter
To convert knots to miles per hour, multiply by 1.150779448; to convert back, multiply by 0.8689762419. For example, 20 kn is about 23.015589 mph. Displayed factors and results may be rounded.
Knots describe nautical miles per hour and are used for marine and aviation speeds. They are a speed unit already, so knots per hour would mean a change in speed. Wind and current can also make speed through water differ from speed over ground.
One knot is one nautical mile (exactly 1,852 m) per hour.
Both units are defined exactly. Calculations use 50 significant digits and round only for display.
How to convert knots to mph
Multiply knots by 1.150779: mph = knots × 1.150779. So 20 knots = 23.02 mph and 50 knots = 57.54 mph. A knot is one nautical mile per hour, and a nautical mile (1,852 m) is about 15% longer than a statute mile, so the mph number is always larger.
Why the factor is 1.150779
A nautical mile is exactly 1,852 m and a statute mile exactly 1,609.344 m (NIST Handbook 44, Appendix C), so one knot is 1852 ÷ 1609.344 = 1.150779448… mph.
The nautical mile began as one minute of latitude, which is why charts and navigation use it.
For mental math, multiply by 1.15. It is within 0.07%: 20 knots gives 23 mph, against 23.0156 with the full factor.
Knots to mph chart
| Knots | Miles per hour, rounded |
|---|---|
| 1 | 1.150779 |
| 5 | 5.753897 |
| 10 | 11.507794 |
| 15 | 17.261692 |
| 20 | 23.015589 |
| 50 | 57.538972 |
Knots to km/h and m/s
One knot is exactly 1.852 km/h, so 20 knots is 37.04 km/h. For meters per second, multiply knots by 0.514444: 20 knots is 10.29 m/s.
Wind speeds in knots and mph
Marine and aviation forecasts usually give wind in knots, while US public forecasts use mph.
The US National Hurricane Center classes a tropical storm from 34 knots (39.13 mph, quoted as 39 mph) and a hurricane from 64 knots (73.65 mph, quoted as 74 mph).
Speed through water vs speed over ground
A boat's log measures speed through the water, while GPS gives speed over ground, and a current makes the two differ. For aircraft, airspeed and groundspeed differ by the wind. The conversion keeps whichever speed you start with.
Common mistakes
- Saying knots per hour. A knot already means per hour, so knots per hour would describe a change in speed.
- Using the reverse factor. 20 knots is not 17.38 mph; that figure is 20 mph expressed in knots.
- Treating nautical miles as statute miles. 10 nautical miles, half an hour at 20 knots, is 11.51 statute miles or 18.52 km.
Related converters
To go from mph to knots, use the speed converter. For road speeds, use mph to km/h.
Worked examples
15 kn to mph
- Knots (kn)
- 15 kn
- Miles per hour
- 17.2616917204 mph
Checked against: Exact-fraction computation from the legal unit definitions
50 kn to mph
- Knots (kn)
- 50 kn
- Miles per hour
- 57.5389724012 mph
Checked against: Exact-fraction computation from the legal unit definitions
Questions
How many miles per hour is one knot?
1 kn is about 1.150779448 mph. One knot is one nautical mile (exactly 1,852 m) per hour.
How do I convert knots to miles per hour?
Multiply by 1.150779448: 20 kn × 1.150779448 ≈ 23.015589 mph. To convert back, divide by the same factor. The factor shown may be rounded.
How can I estimate knots in miles per hour without a calculator?
Multiply by 1.15. This is 0.06773% below the exact factor (about 1.150779448), so 20 kn comes out as 23 mph instead of 23.0156 mph.
About this calculator
Sources
Checked against references
This calculator includes 3 worked examples with independently sourced answers. They run in the test suite, and you can run them here too.