# Nautical miles to Kilometers (nmi to km)

> Convert nautical miles to kilometers: 1 nmi = 1.852 km. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

- Page id: `nautical-miles-to-km` · Quantity: Length (`length`, base unit m) · Tool: `convert_units`
- Canonical page: https://tttkmbb.com/conversion/nautical-miles-to-km · This document: https://tttkmbb.com/conversion/nautical-miles-to-km.md · JSON: https://tttkmbb.com/conversion/nautical-miles-to-km.json (add `?value=` for a result)

## Formula

- `1 nmi = 1.852 km`
- `kilometers = nautical miles × 1.852`
- Reverse: `nautical miles = kilometers × 0.5399568035`

The factor follows from the SI definitions of both units (NIST SP 811); values below are rounded to 6 significant figures, the API returns up to 12.

## Worked examples

- 5 nmi = 9.26 km
- 12.5 nmi = 23.15 km
- 100 nmi = 185.2 km

## Conversion table

| Nautical miles (nmi) | Kilometers (km) |
| --- | --- |
| 1 | 1.852 |
| 2 | 3.704 |
| 3 | 5.556 |
| 4 | 7.408 |
| 5 | 9.26 |
| 6 | 11.112 |
| 7 | 12.964 |
| 8 | 14.816 |
| 9 | 16.668 |
| 10 | 18.52 |
| 15 | 27.78 |
| 20 | 37.04 |
| 25 | 46.3 |
| 30 | 55.56 |
| 40 | 74.08 |
| 50 | 92.6 |
| 75 | 138.9 |
| 100 | 185.2 |
| 200 | 370.4 |
| 250 | 463 |
| 500 | 926 |
| 1000 | 1852 |

## API

- `GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=nmi&to_unit=km` → unified JSON envelope with `result.values.result`, `formula`, `factor`, `sources`, `freshness`
- MCP: server `https://tttkmbb.com/mcp`, tool `convert_units` with `{"value":5,"from_unit":"nmi","to_unit":"km"}`
- All length units: https://tttkmbb.com/api/v1/units?quantity=length · full converter: [Length Converter](https://tttkmbb.com/conversion/length.md)
- Authentication: none. Freshness: `static` (fixed conversion factors).

## FAQ

**How many kilometers are in one nautical mile?**

1 nmi = 1.852 km. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.

**What is the formula to convert nautical miles to kilometers?**

Multiply the value in nautical miles by 1.852: kilometers = nautical miles × 1.852. For example, 5 nmi = 9.26 km.

**How do I convert kilometers back to nautical miles?**

Multiply by the inverse factor 0.5399568035 (nautical miles = kilometers × 0.5399568035), or use the kilometers-to-nautical miles page.

## Related conversions

- [Kilometers to nautical miles](https://tttkmbb.com/conversion/km-to-nautical-miles.md) (reverse)
- [Kilometers to Miles](https://tttkmbb.com/conversion/km-to-miles.md)
- [Miles to Kilometers](https://tttkmbb.com/conversion/miles-to-km.md)
- [Meters to Feet](https://tttkmbb.com/conversion/meters-to-feet.md)
- [Feet to Meters](https://tttkmbb.com/conversion/feet-to-meters.md)
- [Centimeters to Inches](https://tttkmbb.com/conversion/cm-to-inches.md)
- [Inches to Centimeters](https://tttkmbb.com/conversion/inches-to-cm.md)
- [Millimeters to Inches](https://tttkmbb.com/conversion/mm-to-inches.md)
- [Inches to Millimeters](https://tttkmbb.com/conversion/inches-to-mm.md)

## Data Sources

- NIST Special Publication 811 – Guide for the Use of the International System of Units (SI), Appendix B conversion factors — https://www.nist.gov/pml/special-publication-811 (standard, retrieved 2026-09-24)
- BIPM – The International System of Units (SI Brochure, 9th edition) — https://www.bipm.org/en/publications/si-brochure (standard, retrieved 2026-09-24)
- Wikipedia – Conversion of units — https://en.wikipedia.org/wiki/Conversion_of_units (reference, retrieved 2026-09-24)