Which software can be used to draw lines at exact measurements? I am looking for a tool which could be used for example to draw a top down view of the turning circle for a car. The drawing would consist of the outline of the car, at the correct measurements for the scale. e.g. drawn at 1:100

This type of diagram is getting into CAD software territory, I have tried searching for a tool that would be ideal for this but have not seen any programs that let you draw the linework freely while being able to specify line lengths, or use tools to ensure that lines are of exact length / scale

Sketchup Layout is the closest tool I have seen, but it seems to be aimed at drawing architecture and I'm not sure if it is suitable for drawing any linework at known measurements.

Aside from this the only other methods I have seen to achieve this is using grid guides / snapping in Illustrator / gimp / inkscape which is better than nothing, but not really ideal


  • Tried HotDoor's CADTools for Illustrator?
    – Scott
    Commented Oct 15, 2014 at 22:56
  • If you know this is CAD territory then why aren't you looking at... AutoCAD?
    – Ryan
    Commented Oct 15, 2014 at 23:10
  • CADTools looks very promising thanks. Yes fair comment Ryan, I am hoping to find something simpler because the learning curve is quite steep with CAD
    – Andrew
    Commented Oct 15, 2014 at 23:19
  • learning curve of illustrator is comparable to any 2d cad. its only a big deal if you want to use all features. Anyway illustrator can and does allow you to set exact line lengths even without any plugins. just alt click with linetools enabled. Cad software do use snap pretty exclusively also. In general illustrator can do mostly same things as autocad only the geometry solver is missing. If we dont talk of advanced stuff like isometry or 3d. Yes im a cad user.
    – joojaa
    Commented Oct 16, 2014 at 4:51

1 Answer 1


Illustrator is a perfectly viable option for a 2D CAD application (as is Inkscape), in small volumes. The basic difference is that you would not draw the image in 1:100 scale in a CAD application*. Rather you would draw in 1:1 scale and then the print view would be in scale. This speeds up the process since you can just type measured units.

The trick to accurate drawing is to type dimensions in. This is just as possible in Illustrator as it in Autocad or any other CAD application. Cad applications are just slightly more optimized to this, but the difference is not big, with line tool hold alt down and you get the same result.

autocad vs illustrator

Image 1: Autocad (Right) numeric input and Illustrator (Left) numeric input dialog side by side comparison.

Trimming lines is also slightly snappier in a CAD application, but not something you can not overcome with the shape builder tool. Precision in Illustrator is probably ok for your purposes. If you really get pedantic then it suffices to say that Illustrator can not do perfect circles. The deviation is really tiny tough.

Drafting practice

Image 2: An old quick drafting test made to keep my skills up on Illustrator specific workflow. Most measurements deleted to keep the small image as clear as possible.

There is however the question of what your peers use. Sharing is what makes most of our design documents valuable, so use what your peers would use.

* Modern CAD is more modeling than actually drawing anything the CAD handles drawing you just supply the border constraints.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.