Degrees of separation: Notes on the grammar of measurements

Much of the United States was in a deep, deep freeze a couple of weeks ago. If you’ve ever seen a toddler in a snowsuit, that’s exactly how I looked and felt when I walked the dog.

The real-feel temperatures were consistently in the -20°C range and one morning I enjoyed a half-mile walk in -35°C. (Those temps are impressive in Fahrenheit, but they’re even more impressive now that I’ve converted them to Celsius like the civilised world uses.)

Kansas City is now in the 5°C to 15°C range, which I’m loving and the dog is hating. But the point of this Super Grammar isn’t about my physical comfort while walking the dog.

My point is about units of measure and their abbreviations. Did you know, with few exceptions (we’ll talk about those degree symbols above in just a second), The Chicago Manual of Style says a space appears between a numeral and the abbreviation for the unit of measure?

But, there are some exceptions where no spaces are used: 

• Between a numeral, degree symbol and the abbreviation for the unit of temperature
• Between a numeral and a percentage sign
• Between quantities of degrees, minutes, and seconds.

Here’s what all that looks like in action:

• 5 m
• 40 kmh (sometimes seen as kmph)
• 98 kWh
• 300 mg
• -35°C (or -31°F)
• 53%
• 22°14’33”.

How many of us are getting those right when we use them?

May the comforting glow of knowing you’ll get it right from now on keep you warm on those -35°C days.

Wendy Wood
Proofreader

Did you enjoy Super Grammar?

Get a new and super useful grammar tip from our proofreader, Wendy, directly to your inbox once a fortnight in Typeset’s The Write Fit newsletter. Subscribe here: