Length converter
Convert any length between metric, imperial and nautical units with exact factors.
30 Centimetres ≈ 11.81102362 Inches
Exact factorRounded for display to about 10 significant digits.
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About these units
Length is the distance between two points. Its SI base unit is the metre, defined since 1983 by the distance light travels in a vacuum in 1/299 792 458 of a second.
The inch, foot, yard and mile are used in the United States and, for road distances and heights, in the United Kingdom. Since 1959 they are defined exactly in metres: one inch is 2.54 cm. Ships and aircraft use the nautical mile of exactly 1852 metres.
Popular conversions
- Centimetres to Inches
- Inches to Centimetres
- Metres to Feet
- Feet to Metres
- Kilometres to Miles
- Miles to Kilometres
- Millimetres to Inches
- Inches to Millimetres
- Feet to Centimetres
- Centimetres to Feet
- Metres to Yards
- Yards to Metres
- Inches to Feet
- Feet to Inches
- Metres to Inches
- Inches to Metres
- Millimetres to Centimetres
- Centimetres to Millimetres
- Metres to Centimetres
- Centimetres to Metres
- Kilometres to Metres
- Metres to Kilometres
- Nautical miles to Kilometres
- Kilometres to Nautical miles
- Miles to Feet
- Feet to Miles
- Yards to Feet
- Feet to Yards
- Millimetres to Feet
- Micrometres to Millimetres
- Light-years to Kilometres
- Astronomical units to Kilometres
Questions people ask
How many centimetres are in an inch?
Exactly 2.54 centimetres. The inch has been defined this way since the international yard and pound agreement of 1959.
How many feet are in a metre?
About 3.28084 feet. One foot is exactly 0.3048 metres, so a metre is 1 ÷ 0.3048 feet.
What is the difference between a mile and a nautical mile?
A mile is 1609.344 metres; a nautical mile is 1852 metres, roughly one minute of latitude. Knots are nautical miles per hour.
Factors checked 19 October 2026.