Conversion Aversion
Numbers 20 years ago No Comments

Why are so many designers so scared of numbers”  We have a theory here at PLiNTH & CHiNTZ: Some people go into design because they think they can avoid math.  You know who you are.  You think it’s going to be all pretty color palettes and fluffy tassels and gorgeous chandeliers and stuff.


Guess what”  You are sadly mistaken.  But don’t freak out.  It’s OK.  Math isn’t scary because math is beautiful, and math is beautiful because numbers are beautiful.  Not only are they beautiful – they cannot be avoided.  Math is an everyday part of life, so you better grow up and deal with it.  Let us show you how.

Our lesson today deals with conversions: converting one type of quantity / measurement into another.  It’s amazing how many people are easily confused by this. Sure, you can use the handy-dandy conversion website,, that we recommend in our WHAT IN THE WORLD” section, but you need to understand the reasoning behind it.  Why”  Because we said so!  (Oh my gosh, we’re turning into our parents.)  No, really, because you may need to do this on the fly (i.e. in front of other people or on a test without an internet connection in site).  Don’t worry – you can use a calculator.  We’re not THAT sadistic… yet.

Let’s take something simple.  Let’s say that you know the area of a space is 1,557 square feet (typically seen abbreviated as sf or s.f.), and you need to figure out how much carpet is needed.  If you are not aware, carpet is typically measured in square yards, not square feet, and there are 9 sf for every 1 square yard (sy or s.y.) of carpet.  Not to panic.  Solution:

Do you see what we are really doing”  We’re crossing “like” things out:

sf cancels out sf, so what we are left with is sy.  Now this doesn’t take into account ordering a little extra for waste or the width of the room versus the width of the roll, yada yada yada.  That’s for another time, another day, another lesson.  Let’s just talk basic math conversions for the moment.  Estimating will come later.

Now let’s take this a little further.  Let’s get some money involved.  If the carpet is $28 per sy, how much is this going to cost”

which translates into…

All we’re left with is $$$ after we cross out the sy carpet.

One last thing: how much money does this then translate per square foot”  (Clients, contractors and real estate brokers like to know this sort of things because it makes good fodder for their spreadsheets.)

(commonly written $3.11 / sf carpet; said in another way… this carpet costs $3.11 per sf of space)

Of course, to figure these things out the old fashioned way (OK, not quite old fashioned – we ARE using a calculator) you need to have conversion charts from which to work.  We’ll direct you to those later.  Be happy in the moment.

This concept applies to anything, by the way.  Very domestic cooking conversions come to mind first, but you can also use this idea for something as sophisticated as foreign currency conversions: think US dollars into Euros into Italian Lira into the Japanese Yen.  Hey, it could happen!