Nautical Miles to Kilometers (nmi to km) Converter

Nautical Miles to Kilometers

The nautical mile is the standard unit for maritime and aviation distances worldwide. Based on Earth's geography rather than an arbitrary standard, it provides a practical navigation unit that maps directly onto latitude.

One nautical mile equals exactly 1.852 km. This was standardised internationally in 1929.

Why Nautical Miles Exist

Navigation

1 nautical mile = 1 minute of latitude, which simplifies chart reading.

Maritime Law

Territorial waters extend 12 nautical miles from shore.

Aviation

Aircraft distances and speeds use nautical miles and knots.

How to Use This Converter

Enter nautical miles

Type the nmi value in the top field. Kilometres appear instantly below.

Read kilometres

The result updates live to 8 decimal places for GPS and chart plotting.

Copy or swap

Copy for log entries, or swap to convert km back to nautical miles.

Conversion Formula

km = nautical miles × 1.852 • Speed: 1 knot = 1 nmi/h = 1.852 km/h.

Maritime Zones & Voyages

Zone / Voyage	Nautical miles	Kilometres
Territorial waters	12 nmi	22.2 km
Contiguous zone	24 nmi	44.4 km
Exclusive economic zone	200 nmi	370.4 km
Offshore passage	1,000 nmi	1,852 km

Features

Instant As-You-Type Results

The result updates the moment you enter a number — no button to press, no page reload.

One-Click Swap

The swap button between the two fields reverses the direction instantly, so you can convert back without retyping.

Copy Without the Unit

Each field has its own copy button that grabs only the number, ready to paste into forms, spreadsheets, or documents.

Searchable Unit Picker

Each dropdown has a search box — switch to any other length unit and use it as a general-purpose converter.

Maritime & Speed

The Knot

A knot is one nautical mile per hour. A jet cruising at 500 knots travels about 926 km/h.

Sailing Distances

A 50 nmi day sail is 92.6 km; a 1,000 nmi offshore passage is 1,852 km.

Marine-friendly and private. Use it aboard while planning routes — works offline at sea after loading, needs no account, and tracks nothing.

Frequently Asked Questions

How far is 12 nautical miles in km?

12 nautical miles = 22.224 km — the standard territorial-waters limit recognised by international law (UNCLOS).

Why do ships and planes use nautical miles?

Nautical miles relate directly to Earth's coordinates: 1 nautical mile = 1 minute of latitude, making dead reckoning and chart navigation simpler than using kilometres.

What is a knot?

A knot is one nautical mile per hour. The name comes from counting knots on a rope paid out over time to measure ship speed. 1 knot = 1.852 km/h.

Is a nautical mile longer than a regular mile?

Yes. A nautical mile is 1.852 km while a statute (land) mile is 1.609 km — about 15% longer.

How far is the exclusive economic zone?

Countries can claim exclusive economic rights up to 200 nautical miles (370.4 km) from their coast under UNCLOS, affecting fishing rights and resource extraction.

Nautical Miles to Kilometers