I had a bit of a scare the other day: an agency I do a lot of work for sent an important brochure to a proofreader after I’d written all the text for it, and it came back with a few comments. A few things were a matter of style, and then there was one “correction” that caught me off guard.
According to the anonymous guru of grammar, I should have omitted the spaces between numbers and units – so instead of “60cm” it should be “60 cm”. What?
The Guardian style guide
I thought that looked a bit odd, so I turned to the trusty Guardian Style Guide for help. I couldn’t find anything in there, so I thought I’d try asking them on Twitter.
I live to write another day
Their curt but relieving reply was:
No space. https://t.co/yr6JSbFBA6
— Guardian style guide (@guardianstyle) 31. Mai 2016
So it turned out I was right, or at least according to the Guardian. And that’s enough for me.
The International System of Units
Fair play to the proofreader, the International System of Units (SI) – so international that its acronym is French – stipulates that there is a space before an abbreviated unit. However, I wasn’t writing a scientific paper, so just as I ignore the SI when separating thousands with commas, I will ignore it in this case too.
The Telegraph style guide
The Telegraph has a style guide too, and despite being on the other end of the political spectrum from the Guardian, in this they are in agreement: although their style guide doesn’t directly mention it, in the section entitled “Numbers, measures and money”, it clearly departs from the SI and stands shoulder to shoulder with the Guardian: thousands are cleft by commas, and quantities joined to their units.
Conclusion
So there we have it. For non-scientific writing, there’s no space between the number and the unit if it’s abbreviated. If the unit isn’t abbreviated, then – fairly obviously – there is a space. So 60cm or 60 centimetres.