mph to kt Conversion Calculator
Click on the following link if you want to convert knots to miles per hour – kt to mph
History
The mile per hour (mph) was first used in the 17th century in England to measure carriage speeds.
It remains standard in the U.S., U.K., and a few other countries.
The knot (kt), however, was born at sea. Early sailors measured speed with a knotted rope, each knot representing a specific distance based on the nautical mile (1,852 meters).
Today, both mph and knots are officially defined and recognized worldwide.
Common Usage
- mph: used for cars, trains, and land-based speeds.
- knots: used for ships, planes, and weather reporting.
For example, a hurricane wind speed of 100 mph equals 87 knots.
Conversion Formula
To convert mph to knots:
knots = mph ÷ 1.1508
Example:
Convert 50 mph to knots.
50 ÷ 1.1508 = 43.45 knots
So, 50 mph equals 43.45 knots.
Conversion Table
| Miles per Hour (mph) | Knots (kt) |
|---|---|
| 5 mph | 4.35 kt |
| 10 mph | 8.69 kt |
| 20 mph | 17.39 kt |
| 30 mph | 26.08 kt |
| 40 mph | 34.78 kt |
| 50 mph | 43.47 kt |
| 60 mph | 52.17 kt |
| 80 mph | 69.56 kt |
| 100 mph | 86.95 kt |
| 120 mph | 104.34 kt |
Interesting Facts
- Pilots often talk about “airspeed in knots,” even when reporting to ground control.
- 1 knot = 1 nautical mile per hour, making it directly tied to the Earth’s geometry.
- A category 5 hurricane typically exceeds 137 knots (157 mph).
Frequently Asked Questions
1. How many knots are in one mph?
0.868976 knots.
2. How do I convert mph to knots?
Divide by 1.1508.
3. What’s faster: 100 mph or 100 knots?
100 mph is faster (100 kt = 115 mph).
4. Where are knots used most?
In aviation, marine navigation, and meteorology.
5. Are mph and knots interchangeable?
Not directly: knots are tied to the nautical mile, mph to the statute mile.
