How many centimeters are in an inch?

Exactly 2.54. The inch has been defined as 25.4 millimeters since 1959, so 2.54 is not rounded. The inches to centimeters page covers it in more detail.

How many feet are in a mile?

5,280. A mile is also 1,760 yards, 80 chains, 8 furlongs and exactly 1,609.344 meters.

What is the difference between a nautical mile and a mile?

A nautical mile is exactly 1,852 m (1.852 km) and the statute mile is 1,609.344 m, so a nautical mile is about 1.151 statute miles, roughly 15% longer. Ships and aircraft use nautical miles.

Is the US survey foot different from the foot?

Slightly. The US survey foot is 1200/3937 m and the international foot is 0.3048 m, a difference of about 2 parts per million. It only matters for large coordinates and old survey records. For everyday work, use the foot.

Why does another converter show a slightly different answer?

Many round the conversion factor to four or six digits before multiplying. This one multiplies by the exact definition and rounds once, at the end. Use the Precision menu to see more or fewer digits.

Is anything I type stored or sent?

No. Typing sends nothing anywhere: the conversion runs in your browser. Your numbers are also kept in the page address so that Copy link works. That means a link you share, or a page you reload, requests that address, numbers included, from our server like any web address. Share a link only if you are happy to share the numbers.

Length Converter: Meters, Feet, Inches, Miles and More

Conversion chart from inches to centimeters
inch (in)	centimeter (cm)
1	2.54
2	5.08
5	12.7
10	25.4
25	63.5
50	127
100	254
1,000	2,540

inch (in)

centimeter (cm)

2.54

5.08

12.7

25.4

63.5

127

100

254

1,000

2,540

At a glance

What it does

Converts between 20 length units: metric from nanometers to kilometers, imperial and US (thou, inch, foot, yard, mile), nautical and survey units, print units (point, pica) and astronomy units (astronomical unit, light year).

Exactness

Uses exact fractions, so 12 in to cm is exactly 30.48 and not 30.480000000000004. The answer is rounded once, at the end.

Working

Shows the exact relationship between the two units, the multiplication, and the same length in other common units.

Feet and inches

A second calculator below the converter turns 5 ft 9 in into centimeters, and centimeters into feet and inches.

Precision

Automatic, 0 to 10 decimal places, or 3 to 12 significant digits. A height needs one or two decimals, a machined part may need more.

Privacy

Nothing is sent when you type. Your numbers are kept in the page address so Copy link works, so a shared link carries them.

Price

Free, no sign-up.

How to do it

Enter the length

Type or paste a length such as 1,250.5 or 3,5. A comma that groups digits in threes is a thousands separator, so 1,234 means one thousand two hundred thirty-four, and any other single comma is a decimal comma, so 3,5 means 3.5. The "Read as" line under the box shows how your text was read, and the box tells you if it cannot read something.

Choose the units

Pick the From and To units. The menus are grouped into metric, imperial and US, nautical and survey, print and astronomy. The swap button turns the conversion around.

Read the answer and the working

The result updates as you type. Under it you will see the exact relationship, such as 1 ft = 0.3048 m, and the multiplication that gives your answer.

For heights, use feet and inches

Heights are written like 5 ft 9 in, not 5.75 ft. The Feet and inches calculator below the converter handles that in both directions.

The exact definitions behind the numbers

Every length here is tied to the meter. Since 1959 the inch has been defined as exactly 25.4 millimeters, and the foot, yard and mile follow from it with whole numbers: 1 ft = 12 in = 0.3048 m, 1 yd = 3 ft = 0.9144 m and 1 mi = 5,280 ft = 1,609.344 m. These are definitions, not measurements, so the conversions are exact.

The converter keeps them as fractions instead of floating point numbers. That is why you will not see answers like 30.480000000000004, and why a round trip from inches to centimeters and back returns exactly what you typed.

Other units are definitions too. The nautical mile is exactly 1,852 m, the astronomical unit exactly 149,597,870,700 m, and the light year exactly 9,460,730,472,580,800 m, which is 9,460,730,472,580.8 km.

Imperial, US and survey units compared

Inch, foot, yard and mile are the international units used for everyday lengths in the US and for road distances and heights in the UK.
The US survey foot is defined as 1200/3937 m, about 2 parts per million longer than the international foot, which adds up to roughly 3 mm over a mile. It was phased out in the US at the end of 2022. It is listed on its own so that old land survey figures can still be converted correctly.
Chain, furlong and fathom are surveying, farming and sailing units: 66 ft, 660 ft and 6 ft. Furlongs are still used for horse races in the UK.
Point and pica are printing units, 1/72 inch and 1/6 inch. They are what the sizes in a layout program are measured in.
The nautical mile is exactly 1,852 m, about 1.151 statute miles. One nautical mile per hour is one knot.

Quick estimates that are close enough

When you do not need an exact figure, these are close enough for a rough idea, with an error under 4 percent:

1 inch is 2.5 cm (really 2.54) and 1 foot is 30 cm (really 30.48).
1 meter is a little over 3 feet 3 inches: exactly 3 ft 3.37 in.
1 mile is about 1.6 km (really 1.609344) and 1 km is about 0.6 miles (really 0.6214).
1 yard is just under a meter: 0.9144 m.

For anything that is bought, cut or built, use the exact answer from the converter above.

Length converter