Percentages: Do The Maths

These exchanges probably sound very familiar :
Sam:   Are you sure you want to go?
Jo:       Yep. Totally… 110%
Mal:     Is this a really committed relationship?
Toni:    Absolutely… 1,000%
A mathematical impossibility – in both cases.
It’s also a valid language concern.

In the examples, above, the speakers are sure about their positions – very sure. They feel the need to emphasise their certainty but they don’t understand that words like ‘totally’ and ‘absolutely’ already do that. These are adverbs that convey a ‘complete degree’ of certainty or commitment. 
To add something, for extra emphasis, is fine; it’s what we tend to do, especially in spoken language. Saying ‘100%’ – which is a colloquial way of saying ‘completely’ – does just that.

A percentage figure over 100, though, is just nonsense in these cases.

Mathematical  percentages 

Percentages over 100 are possible, of course, but only make sense when we’re talking about number-related amounts (countables) – in terms of increases or when making comparisons.
For example:

  • Our landholdings increased by 110% – from 50 to 105 hectares
  • Revenue went from $2 million to $5 million this year; that’s an increase (or improvement) of 150%
  • Charitable donations rose from 100 items in the first month to a massive 5,100 two years later; an increase of 5,000%

 Remember that the language we use also matters .

The key thing here is the difference between saying ‘an increase of x% (as above) or ‘x% more than’  and ‘x% of’.  

Here’s an example:

  • We compared our salaries. I earn $100,000 p.a. My sister’s salary is 110% of mine, at $110,000 (i.e. a 10% increase).

(Note, if my sister’s salary were 110% more than mine, it would be $210,000) 

NB: It’s impossible to have more than 100% reduction in anything. 

If the maths part of the whole business is a bit baffling, you’ll find help here.

Find out more about Countable Nouns.

And see more ways to Be Word Wise.