 Convert Kilometres (km) to Millimetres (mm) | km in mm
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# Let's convert Kilometres (km) to Millimetres (mm)

This quick and easy calculator will convert Kilometres (km) to Millimetres (mm) and show formula, brief history on the units and quick maths for the conversion.

## Quick Reference for Converting Kilometres to Millimetres

Formula
mm = km x 1000000
Quick Rough Maths
To get the Millimetres, multiply the number of Kilometres by 1000 thousand
Kilometres (km) in 1 Millimetre
There are 0 Kilometres in 1 Millimetre
Millimetres (mm) in 1 Kilometre
There are 1000000 Millimetres in 1 Kilometre

## Unit Information

Kilometre
/ˈkɪləˌmiːtə,kɪˈlɒmɪtə/
Symbol: km
Unit System: SI

### What is the Kilometre?

The kilometre is a unit of length and is a multiple of the metre; an SI derived unit. It has the symbol km.

A kilometre is equal to 1000m, 1094 yards and 0.621 miles.

Kilometres is used to measure road distances in the US, though the UK is still using the imperial "sister" miles.

Millimetre
/ˈmɪlɪmiːtə/
Symbol: mm
Unit System: SI

### What is the Millimetre?

The millimetre (American spelling millimeter) is a unit of length and is a multiple of the SI unit metre. It uses the symbol mm.

There are 1000 mm in 1 m and 10 mm in 1 cm. From this one can derive that there are 0.03937 in.

The millimetre is sometimes verbally abbreviated to 'mil' - which can cause confusion in the US as there is a unit there that means thousandth of an inch.