Length Converter

This free online length conversion tool makes it simple to convert a length measurement into a wide range of commonly used metric and imperial units. Whether you’re working on a construction project, studying mathematics, designing layouts, or converting international measurements, this calculator provides fast and accurate results.

With this length calculator, you can easily convert between Millimetres, Centimetres, Metres, Kilometres, Inches, Feet, Yards, and Miles. Simply enter a value into any of the available input fields, and the calculator will instantly convert and display the equivalent values across all other length units. This real-time conversion removes the need for manual calculations and ensures consistent, reliable measurements.

Enter length

Millimetre

Inch

Centimetre

Foot

Metre

Yard

Kilometre

Mile

Decimal places

Calculated in your browser as you type. Very small results can show as 0 when rounded to few decimal places.

How to use it

The length conversion calculator is a handy webtool to use to convert from one length to another.

Enter a valueType a length into any one of the fields. Any number is accepted, including the ‘e’ exponent such as 1e3.
Read the resultsAll the other fields update automatically with the converted lengths.
Copy a valueClick the clipboard button beside any field to copy it.
Tidy the numbersUse Decimal places to round the results, or leave it on full precision.

Handy conversions

1 inch

Is exactly 2.54 centimetres, or 25.4 millimetres.

1 foot

Is exactly 30.48 centimetres, or 12 inches.

1 mile

Is exactly 1.609344 kilometres, or 1,760 yards.

Length unit comparison table

Unit name	Symbol	Description	Equals in metres
Millimetre	mm	Small metric unit commonly used for precision	`0.001 m`
Centimetre	cm	Metric unit often used for everyday measurements	`0.01 m`
Metre	m	Base unit of length in the metric system	`1 m`
Kilometre	km	Used for long distances and travel	`1,000 m`
Inch	in	Small imperial length unit	`0.0254 m`
Foot	ft	Common imperial unit for height and room dimensions	`0.3048 m`
Yard	yd	Imperial unit often used in sports and landscaping	`0.9144 m`
Mile	mi	Used for long-distance travel (imperial)	`1,609.344 m`

Useful notes

Metric and imperial

Metric units are used worldwide for science, engineering and general measurements. Imperial units are primarily used in the United States and parts of the UK.

Small measurements

Millimetres and centimetres are ideal for small, precise measurements.

Long distances

Kilometres and miles are commonly used for large distances such as road travel.

Frequently asked questions

How many centimetres are in an inch?

One inch is exactly 2.54 centimetres. To convert inches to centimetres multiply by 2.54, and to convert centimetres to inches divide by 2.54.

How many feet are in a mile?

One mile is exactly 5,280 feet, which is also 1,760 yards and 63,360 inches.

How many kilometres are in a mile?

One mile is exactly 1.609344 kilometres. A quick estimate is that 10 miles is about 16 kilometres.

Are the conversions exact?

The imperial units here are defined in terms of the metre (1 inch = 25.4 mm exactly), so the results are exact apart from normal computer rounding. The US survey foot, used in some land surveys, differs very slightly.

Can I type very large or very small numbers?

Yes. Any number is accepted, including scientific notation such as 1e6 or 2.5e-3.

Is anything sent to a server?

No. The conversion is calculated in your browser as you type.