Fidamen

Convert Nautical Miles to Kilometers – Length Converter

Convert nautical miles to kilometers using maritime navigation standards where distance is tied to Earth geometry and charting conventions; nautical miles remain standard in marine and aviation navigation, voyage planning, and regulatory reporting, and this converter applies the fixed definition to deliver accurate, SI-compatible distances for calculations and logs.

Updated Nov 4, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record fb8cd6f391f5 • Reviewed by Fidamen Standards Committee

Interactive Converter

Convert between nautical mile and kilometer with precision rounding.

Quick reference table

Nautical MileKilometer
NMI 1.00 nmi1.852 km
NMI 5.00 nmi9.26 km
NMI 10.00 nmi18.52 km
NMI 25.00 nmi46.3 km
NMI 50.00 nmi92.6 km
NMI 100.00 nmi185.2 km

Methodology

By international convention the nautical mile is defined as exactly 1852 metres. That definition is used by national standards bodies and international organizations for navigation and mapping. Converting to kilometres therefore reduces to a fixed scalar multiplication: multiply nautical miles by 1.852 to get kilometres.

When reporting or using converted distances in regulated contexts, follow local measurement traceability and documentation requirements. For engineering or safety-critical uses follow guidance from recognized standards organizations (for example NIST for unit definitions and uncertainty, ISO for quantities and units, IEEE when communicating units in technical documents, and OSHA where metric reporting is required for safety records).

Key takeaways

The nautical mile → kilometre conversion uses an exact scalar (1 nmi = 1.852 km).

Use appropriate rounding and record uncertainty when converting for reporting, regulatory or safety purposes.

Refer to the cited standards for authoritative definitions and requirements for traceability and unit notation.

Worked examples

1 nmi → 1 × 1.852 = 1.852 km

0.5 nmi → 0.5 × 1.852 = 0.926 km

10 nmi → 10 × 1.852 = 18.52 km

100 nmi → 100 × 1.852 = 185.2 km

F.A.Q.

Is the conversion between nautical miles and kilometres exact?

Yes. By international agreement one nautical mile is defined as exactly 1,852 metres, so converting to kilometres (1 km = 1,000 m) yields an exact factor of 1.852. Any non-exactness in results comes from numeric rounding when displaying values.

Where does the value 1.852 come from?

Historically the nautical mile was defined relative to the Earth's circumference; the modern international nautical mile has been fixed at 1,852 metres by international standards bodies. See the cited standards for the formal definition and history.

How many decimal places should I use?

Choose precision based on context: navigation and charting often use one or two decimal places for operational readability, while engineering or scientific work should include uncertainty estimates and use enough precision to reflect measurement tolerances. When in doubt, keep at least three significant digits and document rounding.

When should I use nautical miles instead of kilometres?

Nautical miles are standard in marine and aviation contexts because they relate directly to minutes of latitude and navigation charts. Use kilometres for land-based metric reporting or when mandated by regulatory or engineering standards.

Do I need to record measurement uncertainty when converting?

Yes for regulated, safety-critical, or precision engineering contexts. Converting the unit itself is exact, but the original distance may carry measurement uncertainty. Follow guidance from standards bodies (for example NIST and ISO) when documenting uncertainty and traceability.

Sources & citations

Further resources

Versioning & Change Control

Audit record (versions, QA runs, reviewer sign-off, and evidence).

Record ID: fb8cd6f391f5

What changed (latest)

v1.0.0 • 2025-11-04 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Public QA status

PASS — golden 25 + edge 120

Last run: 2026-01-23 • Run: golden-edge-2026-01-23

Engine

v1.0.0

Data

Baseline (no external datasets)

Content

v1.0.0

UI

v1.0.0

Governance

Last updated: Nov 4, 2025

Reviewed by: Fidamen Standards Committee (Review board)

Credentials: Internal QA

Risk level: low

Reviewer profile (entity)

Fidamen Standards Committee

Review board

Internal QA

Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person

Semantic versioning

  • MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
  • MINOR: New features or fields that do not change existing outputs for the same inputs.
  • PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.

Review protocol

  • Verify formulas and unit definitions against primary standards or datasets.
  • Run golden-case regression suite and edge-case suite.
  • Record reviewer sign-off with credentials and scope.
  • Document assumptions, limitations, and jurisdiction applicability.

Assumptions & limitations

  • Uses exact unit definitions from the Fidamen conversion library.
  • Internal calculations use double precision; display rounding follows the unit's configured decimal places.
  • Not a substitute for calibrated instruments in regulated contexts.
  • Jurisdiction-specific rules may require official guidance.

Change log

v1.0.0 • 2025-11-04 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: 5e321a45ca66