Urban planning community | #theplannerlife

# Thread: Scale conversion question

1. ## Scale conversion question

a puzzler: I've blown up a drawing which had a scale of one inch= 1,000 ft.
It was enlarged by 175%. What is the new scale?

Dave

2. Sounds like one of my GMAT practice questions.

Should work out that 1 inch = 571 ft. (1000/175)

I know my first reflex was to say 1=1750 but if you "blow" something up the scale has to shrink (ie the unit become smaller). No wonder I'm finding the math sections difficult, and yet another reason I leave scale to my techs.

3. If I just had a 1:571 scale, I'd be in hog heaven.

Most US scales are 1:10, 20 ... 60 (or 100 ... 600) If you want to save time and consternation, reduce or enlarge with these scales in mind.

I once got a record plat scaled at 1:75 Rejected it out of hand

4. Hum.. shouldn't numerical scales be represented with the same units in both sides? Otherwise you'd have dumb and misleading scales of 1:1 that are actually 1 inch=1 mile.
Also a small tip that can be used in both metric and crappy imperial systems: draw a graphical scale when enlarging or shrinking... so that way you can easily get the numerical one with just a ruler.