Calculators
Length Converter
Convert any length or distance between millimetres, centimetres, metres, kilometres, inches, feet, yards, miles, nautical miles and light-years. All conversions update as you type.
About the Length Converter
Convert any length or distance between metric units (millimetres to kilometres), imperial units (inches to miles), nautical miles and light-years. All conversions update instantly as you type.
Key length conversions
1 inch = 2.54 cm exactly (defined). 1 foot = 12 inches = 30.48 cm. 1 yard = 3 feet = 91.44 cm. 1 mile = 5,280 feet = 1,609.344 m exactly.
1 nautical mile = 1,852 m exactly — it equals one arcminute of latitude and is used in maritime and aviation navigation.
1 light-year ≈ 9.461 × 10¹⁵ metres — the distance light travels in a vacuum in one year. Used in astronomy; not to be confused with a unit of time.
Frequently asked questions
How many cm in an inch?
Exactly 2.54 centimetres. This is a defined (exact) conversion — 1 inch = 2.54 cm with no rounding.
How many kilometres in a mile?
Exactly 1.609344 kilometres. 1 mile = 5,280 feet = 1,609.344 metres.