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Conversion Formula:
Convert Chain to Nautical Mile (ch to nmi) instantly with accurate, readable results.
Use our Length Unit Converter to quickly convert between meters, kilometers, feet, inches, miles, and more. This powerful unit conversion tool supports both metric and imperial systems, making it ideal for travel, engineering, education, and everyday use. Whether you're calculating distances or comparing measurements, our length unit conversion calculator ensures fast and accurate results every time.
Chain - traditional surveying length unit
Chain is a historical unit used in land surveying, specifically Gunter’s chain. Used on cadastral maps and by railways and surveyors across the English-speaking world.
- Symbols: ch (common)
- System: Imperial/US customary (historic surveying)
- Exact relations: 1 chain = 66 ft = 22 yd = 4 rods = 100 links = 1/80 mile; 10 chains = 1 furlong
- Metric equivalents: 1 chain = 20.1168 m (exact)
- Typical examples: UK railway distances recorded in miles and chains; a cricket pitch length is 1 chain (22 yd)
Nautical mile (nmi) — unit for marine and air navigation defined exactly as 1,852 meters
Closely tied to Earth’s geometry; one minute of latitude is approximately one nautical mile. Speeds at sea and in air use knots.
- Symbols: nmi, NM
- Systems: Maritime/Aviation
- Exact relations: 1 nmi = 1,852 m = 1.852 km (exact)
- Imperial/US equivalents: 1 nmi ≈ 1.15078 mi ≈ 6,076.11549 ft
- Typical examples: charted distances; 1 knot = 1 nmi/h