How to Find the Scale

May 24 2019   12 PM  

It’s not always easy to get the original copies of plans straight from the draftys pen, sometimes  originals have been scanned and re-uploaded which will affect you when you are looking to get accurate measurements, other times guys send you a picture of plans (As in the  example below). It can be a real slog getting the correct information for something so crucial that could be the difference in thousands of dollars.

If you are using ConX measure the system will automatically read the size of the page and you can enter the correct scale. However if measurements are off due to whatever reason, we have a solution. We have gone back to our high school maths books and picked out a pretty handy formula for getting the scale as close to accurate as possible without having the original plans.


Formula to find correct scale

Find a known measurement on the page eg 6.0m

Using the length tool, measure the line and see what comes out using the scale 1:100 -  eg 5.2m

Divide the known measurement: 6.0m by the ConX measurement” 5.2m


6 divided by 5.2

= 1.1538

Multiply that by 100

= 115.38


and that's the scale. 1:115 and you should get accurate measurements. Be sure to test it again on a know measurement to make sure it is correct.

So here’s the formula:

The Scale = (“Known Measurement” ÷ “ConX Measurement”) x 100


Hopefully that helps you going forward! Feel free to reach out if you have any other questions!

(We even helped this guy measure using mobile images of contruction plans)