Mile/h to Knot Converter
Enter the value that you want to convert mile/h (mi/h) to knot (kt) or knot to mile/h.Also written as MI/H to KT conversion.
1 mile/h = 0.8689762 knot
Formula: knot = mile/h value × 0.8689762
MI/H to KT — mile/h to knot
10 mile/h = 8.68976 knot
Popular Speed Converters:
Converting Mile/h to Knot
The Mile/h Explained
The mile per hour (mph) is the standard speed unit for road transport in the United States, United Kingdom, and a few other countries.
US speed limits range from 25 mph in residential areas to 85 mph on some Texas highways. In motorsport, NASCAR top speeds exceed 200 mph, and Indy cars reach 240 mph. The UK uses mph for all road signs despite otherwise adopting metric. Baseball pitch speeds and hurricane categories are also measured in mph.
Understanding the Knot
The knot (1 nautical mile per hour) is the universal speed unit for maritime navigation and aviation worldwide.
One knot equals exactly 1.852 km/h or 1.15078 mph. The name comes from the historical practice of measuring ship speed by counting knots on a rope pulled overboard. All aircraft airspeed indicators display in knots, air traffic control communicates in knots, and nautical charts are designed around the nautical mile. Tropical storm wind speeds are officially reported in knots.
Speed Unit Conversions
Speed units vary by transport mode and country. Automobiles use km/h in most countries but mph in the US and UK. Aviation uses knots worldwide. Shipping uses knots for surface speed. Physics calculations require meters per second. Wind speeds appear in km/h, mph, knots, or Beaufort scale depending on the meteorological service. Sports timing uses m/s for track events but km/h or mph for ball speeds.
mile/h to knot metric conversion table
| 0.01 mi/h | = | 0.00869 kt |
| 0.1 mi/h | = | 0.08690 kt |
| 1 mi/h | = | 0.86898 kt |
| 2 mi/h | = | 1.73795 kt |
| 3 mi/h | = | 2.60693 kt |
| 4 mi/h | = | 3.47590 kt |
| 5 mi/h | = | 4.34488 kt |
| 6 mi/h | = | 5.21386 kt |
| 7 mi/h | = | 6.08283 kt |
| 8 mi/h | = | 6.95181 kt |
| 9 mi/h | = | 7.82079 kt |
| 10 mi/h | = | 8.68976 kt |
| 11 mi/h | = | 9.55874 kt |
| 12 mi/h | = | 10.42771 kt |
| 13 mi/h | = | 11.29669 kt |
| 14 mi/h | = | 12.16567 kt |
| 15 mi/h | = | 13.03464 kt |
| 16 mi/h | = | 13.90362 kt |
| 17 mi/h | = | 14.77260 kt |
| 18 mi/h | = | 15.64157 kt |
| 19 mi/h | = | 16.51055 kt |
| 20 mi/h | = | 17.37952 kt |
| 30 mi/h | = | 26.06929 kt |
| 40 mi/h | = | 34.75905 kt |
| 50 mi/h | = | 43.44881 kt |
| 60 mi/h | = | 52.13857 kt |
| 70 mi/h | = | 60.82834 kt |
| 80 mi/h | = | 69.51810 kt |
| 90 mi/h | = | 78.20786 kt |
| 100 mi/h | = | 86.89762 kt |
| 200 mi/h | = | 173.79525 kt |
| 300 mi/h | = | 260.69287 kt |
| 400 mi/h | = | 347.59050 kt |
| 500 mi/h | = | 434.48812 kt |
| 600 mi/h | = | 521.38575 kt |
| 700 mi/h | = | 608.28337 kt |
| 800 mi/h | = | 695.18099 kt |
| 900 mi/h | = | 782.07862 kt |
| 1000 mi/h | = | 868.97624 kt |
How to Convert MI/H to KT (Mile/h to Knot)?
We can convert mile/h to knot by using an example.
Example:
Convert 20 Mile/h to Knot?
We know 1 Mile/h = 0.8689762 knot; 1 Knot = 1.1507794 mile/h.
20 mile/h = ___kt
20 × 0.8689762 = 17.37952 kt (we know 1 mile/h = 0.8689762 knot)
Answer:
20 mile/h = 17.37952 knot
How to Convert mph to Knots (Step-by-Step)
Converting miles per hour to knots is needed for boaters interpreting weather forecasts, pilots filing flight plans, and anyone working with maritime or aviation speed standards. The conversion factor is 0.868976 (or divide by 1.15078).
- Write down the speed value in miles per hour (mph).
- Multiply the mph value by 0.868976 (or divide by 1.15078).
- The result is the equivalent speed in knots.
- For a quick estimate, subtract about 13% from the mph value.
Common mph to Knots Conversions
Reference table for converting common American speeds to the nautical knot measurement.
| Mile/h | Knot |
|---|---|
| 10 mph | 8.69 knots |
| 25 mph | 21.72 knots |
| 50 mph | 43.45 knots |
| 70 mph | 60.83 knots |
| 74 mph | 64.30 knots |
| 100 mph | 86.90 knots |
| 150 mph | 130.35 knots |
| 500 mph | 434.49 knots |
Solved Examples: mph to Knots
Question 1: A speedboat travels at 70 mph. Convert to knots for maritime communication.
Solution:
Formula: knots = mph × 0.868976
= 70 × 0.868976
= 60.83 knots
Answer: 70 mph = 60.83 knots
Question 2: Fishing regulations set a 5 mph speed limit in the marina. What is this in knots for your chart plotter?
Solution:
knots = mph × 0.868976
= 5 × 0.868976
= 4.34 knots
Answer: 5 mph = 4.34 knots (typical no-wake speed)
Question 3: Tropical storm winds reach 60 mph. Convert to knots for the National Hurricane Center.
Solution:
knots = mph × 0.868976
= 60 × 0.868976
= 52.14 knots
Answer: 60 mph = 52.14 knots (below the 64-knot hurricane threshold)
Question 4: A private plane has a cruise speed of 180 mph. What is this in knots for the flight plan?
Solution:
knots = mph × 0.868976
= 180 × 0.868976
= 156.42 knots
Answer: 180 mph = 156.42 knots
Practice Questions
Try solving these on your own to test your understanding:
- Convert 35 mph to knots. (Answer: 30.41 knots)
- A hurricane has 157 mph winds. What is this in knots? (Answer: 136.43 knots)
- Convert 20 mph (typical sailboat) to knots. (Answer: 17.38 knots)
- An aircraft descends at 250 mph. Convert to knots. (Answer: 217.24 knots)
- Convert 45 mph lake speed limit to knots. (Answer: 39.10 knots)
Speed Limits on Water
Unlike roads, speed limits on water vary widely by jurisdiction and location. US waterways commonly enforce: 5 mph (4.3 knots) no-wake in marinas and near docks, 25-35 mph (22-30 knots) in channels and near shore, and unlimited speed in open waters. The US Coast Guard and state marine patrols enforce these limits. Some lakes impose blanket speed limits (often 35-45 mph or 30-39 knots). Near swimmers, most jurisdictions require idle/no-wake speed within 100-200 feet. These limits are often posted in mph in the US but GPS chart plotters display knots.
Why Boat Speed Feels Different Than Car Speed
Boat speed feels very different from car speed due to wind exposure, wave impact, and the lack of a fixed reference frame. A boat doing 30 knots (34.5 mph) feels much faster than driving 35 mph in a car. This is important for safety — what seems like a moderate car speed can be dangerously fast on water. Additionally, stopping distance on water is far greater than on land because boats have no brakes. At 30 knots, a typical powerboat needs 100-200 feet to stop completely.
GPS and Marine Navigation Units
Marine GPS chart plotters default to knots and nautical miles. When a US boater is accustomed to thinking in mph, the GPS reading can be confusing. Most marine GPS units can be switched to display mph, but nautical charts, AIS transponders, and VHF weather broadcasts all use knots. The best practice is to become comfortable with both units. A helpful reference: multiply your GPS knot reading by 1.15 to get approximate mph, or set your GPS to show both units simultaneously if the device supports it.
Key Takeaways
- Multiply mph by 0.868976 to get knots (or divide by 1.15078).
- Quick estimate: subtract about 13% from the mph value.
- 74 mph = 64 knots — the hurricane threshold in both unit systems.
- US boat speedometers often display mph while charts and GPS use knots.
- Water speed limits in the US are posted in mph but maritime comms use knots.
- 1 knot = 1 nautical mile/hour = 1.15078 mph (the inverse relationship).
Mile/h to Knot Conversion Formula
knot = mile/h × 0.8689762
1 mile/h = 0.8689762 knot
1 knot = 1.1507794 mile/h
Reverse: mile/h = knot × 1.1507794
Frequently Asked Questions
How many knot are in 1 mile/h?
There are 0.8689762 knot in 1 mile/h. To convert mile/h to knot, multiply the value by 0.8689762.
How do I convert mile/h to knot?
Multiply your mile/h value by 0.8689762 to get the equivalent in knot. For example, 5 mile/h = 5 × 0.8689762 = 4.34488 knot.
How do I convert knot to mile/h?
Multiply your knot value by 1.1507794 to get the equivalent in mile/h. Alternatively, divide by 0.8689762.
What is 10 mile/h in knot?
10 mile/h is equal to 8.68976 knot.
What is 100 mile/h in knot?
100 mile/h is equal to 86.89762 knot.