What is 15mm in Ems?

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What is 15 Millimetres (15mm) in Ems (em)?

What is 15mm in em? Convert 15 Millimetres (15mm) to Ems (em) and show formula, brief history on the units and quick maths for the conversion.

Enter Millimetres to convert to Ems


Quick Reference for Converting Millimetres to Ems

Formula
em = mm / 4.23
Quick Rough Maths
To get the Ems, divide the number of Millimetres by 4.2
Millimetres (mm) in 1 Em
There are 4.23 Millimetres in 1 Em
Ems (em) in 1 Millimetre
There are 0.24 Ems in 1 Millimetre

Unit Information

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.

Em
/ɛm/
Symbol: em
Unit System: Typography

What is the Em?

The em is a unit of length in the field of typography and uses the symbol em.

It is a "relative" unit and equals the currently specified point size. For example, 1 em in a 24-point typeface is equal to 24 points. This allows a typographer to specify text size relative to a base figure.

In metal type, the em was equal to the line height of the metal body. This meant the physical size of the letter could not exceed the em. In digital type, the em is a grid of arbitrary resolution so can be scaled to any point size for screen or print.


Conversion Tables for Millimetres (mm) to Ems (em)