How many km/h is one knot?

Exactly 1.852 km/h, because a nautical mile is exactly 1,852 meters. That is also about 1.15 mph. To convert any knots value to km/h, multiply by 1.852; for mph, multiply by 1.15078.

Why do ships and planes use knots instead of km/h?

Because navigation charts use nautical miles, and one nautical mile equals one minute of latitude. A navigator can measure distance straight off the latitude scale on the chart, so speed in knots (nautical miles per hour) keeps the whole system consistent.

How fast is 100 knots?

100 knots equals 185.2 km/h, or about 115 mph. It is a common speed for a light aircraft on approach. Just multiply the knots figure by 1.852 for km/h or by 1.15078 for mph.

Is a knot the same as a nautical mile?

No. A nautical mile is a distance (1,852 meters); a knot is a speed of one nautical mile per hour. Saying knots per hour is incorrect, since the per hour is already built into the knot.

Knots to km/h: The Conversion and Where Knots Are Used

Published 5/21/2026 · 4 min read · Car calculators

Marco Bianchi — Home, DIY & motoring writer at OneKitly

Renovation · Materials

Checked against 2 sources

View profile →

In short

One knot is exactly 1.852 kilometers per hour, and about 1.15 miles per hour. A knot is one nautical mile per hour, and the nautical mile — 1,852 meters — is defined from the size of the Earth: it equals one minute of latitude. To convert, multiply knots by 1.852 to get km/h, or by 1.15078 to get mph. So 100 knots is 185.2 km/h or about 115 mph, and 20 knots is 37 km/h or about 23 mph. Knots are the standard speed unit in aviation and at sea worldwide, because navigation charts are laid out in nautical miles, which map cleanly onto latitude and longitude.

One knot equals exactly 1.852 km/h and about 1.15 mph. See the exact conversion factor, why the nautical mile exists, and where aviation and shipping use knots.

The exact factor and how to use it

The conversion is not an approximation: one knot is defined as exactly 1.852 km/h, because a nautical mile is exactly 1,852 meters. To go from knots to km/h, multiply by 1.852; to go from knots to mph, multiply by 1.15078. Reverse the direction by dividing: km/h ÷ 1.852 gives knots, and mph ÷ 1.15078 gives knots.

For quick mental math, a knot is a little under 2 km/h, so doubling knots gives a rough km/h upper bound. A 15-knot wind is about 28 km/h (roughly 17 mph); a cruising jet at 470 knots is about 870 km/h (about 540 mph). When you need precision — filing a flight plan, reading a marine forecast — use the exact 1.852 factor rather than the doubling shortcut.

Why the nautical mile exists

The nautical mile is tied to the shape of the planet. Circles of latitude are divided into degrees and minutes, and one minute of latitude spans almost exactly one nautical mile. That link is what makes it so useful for navigation: on a chart, a navigator can step off distance directly against the latitude scale in the margin, no conversion needed.

The name knot comes from an old measuring tool: sailors trailed a rope with evenly spaced knots and a wooden log behind the ship, then counted how many knots ran out in a fixed time to read the speed. The unit stuck. Today knots are formally accepted for use alongside the SI even though they are not an SI unit, precisely because navigation still leans on nautical miles.

Where you will meet knots

Aviation uses knots for airspeed and wind everywhere, so an airliner cruising at 470 knots is doing about 870 km/h. Air traffic control, altimeters and flight plans all speak knots regardless of country. At sea, ship speed and current are given in knots, and marine weather quotes wind speed in knots too — a gale warning at 40 knots means roughly 74 km/h.

You will also see knots in weather reports for storms and hurricanes, in wind data for sailing and kitesurfing, and on GPS units that offer a knots mode. Everyday car speeds, by contrast, stay in km/h or mph — nobody quotes a highway limit in knots. Knowing the 1.852 factor lets you translate a marine or aviation figure into the road units you think in.

Speed converterConvert between km/h, mph, m/s, kn and more. Free speed converter, instant and accurate.Try the tool →

Frequently asked questions

How many km/h is one knot?: Exactly 1.852 km/h, because a nautical mile is exactly 1,852 meters. That is also about 1.15 mph. To convert any knots value to km/h, multiply by 1.852; for mph, multiply by 1.15078.
Why do ships and planes use knots instead of km/h?: Because navigation charts use nautical miles, and one nautical mile equals one minute of latitude. A navigator can measure distance straight off the latitude scale on the chart, so speed in knots (nautical miles per hour) keeps the whole system consistent.
How fast is 100 knots?: 100 knots equals 185.2 km/h, or about 115 mph. It is a common speed for a light aircraft on approach. Just multiply the knots figure by 1.852 for km/h or by 1.15078 for mph.
Is a knot the same as a nautical mile?: No. A nautical mile is a distance (1,852 meters); a knot is a speed of one nautical mile per hour. Saying knots per hour is incorrect, since the per hour is already built into the knot.

Articles you may find interesting

All guides →

How-toHow to Recover from Jet Lag: A Time-Zone Reset PlanJet lag eases at roughly one day per time zone crossed. Learn why eastward travel is harder, and follow a light, sleep and meal plan to reset your body clock faster.How-toHow to Estimate Flight Time: Distance, Cruise Speed and OverheadEstimate a flight's duration by dividing the great-circle distance by cruise speed, then adding taxi, climb and descent overhead. A simple, reliable method.How-toHow to Improve Fuel Economy: Driving Habits That Actually SaveSmoother driving, correct tire pressure, less weight and lower motorway speed can cut fuel use noticeably. Here is what each one is worth.ExplainerTorque vs Horsepower: What Each One Actually DoesTorque is the twisting force an engine makes; horsepower is how fast it does work. Learn the hp = torque × rpm ÷ 5252 link and why both numbers matter.Explainermph to km/h: The Conversion Factor and Mental-Math TricksConvert miles per hour to kilometers per hour and back with the exact factor 1.609, common speed limits in both systems, and quick tricks you can do in your head.ExplainerBandwidth and Speed: Mbps vs MB/s ExplainedWhy your 100 Mbps plan downloads at 12.5 MB/s, the bits-versus-bytes ÷8 rule, and how to turn a connection speed into a real download time.

Sources

Spotted a mistake in this article?