Convert inch to nautical mile

Common mistakes in length conversion

• The problem is that 5.5 feet is often mistakenly interpreted as 5 feet 5 inches. However, the decimal part represents a fraction of a foot, not inches. Since one foot equals 12 inches, 0.5 feet = 6 inches, so 5.5 feet is actually 5 feet 6 inches. To convert decimal feet correctly, multiply the fractional part by 12 to get the number of inches.
• A nautical mile is 1,852 m, defined from one minute of arc along a meridian, while the statute mile is about 1,609 m. Sea and air distances always use nautical miles, so 100 NM is 185.2 km, roughly 15% longer than 100 statute miles. Check which mile a chart or spec is using before you convert.
• Rounding the inch to 2.5 cm feels harmless, but the exact value is 2.54 cm, a 1.6% error. Over a 100-inch measurement that is already 4 cm off, and the error compounds in chained calculations. Use the exact definition: 1 inch = 2.54 cm, exactly.