HELP with Image Map Coordinates!

Help! I am trying to create an image map using image-map.net. I am not having issues creating the actual image map and collecting the code, but when I bring that into my website in squarespace, I cannot for the life of me figure out how to get the coordinates accurate (they clearly aren't aligning from what I create in image-map.net over toe squarespace). Hoping there is a reasonably easy solution to this. 
Note: As you can see from the image that I'm looking to map from, this is a subdivision plot with hundreds of homes, and I'm looking to create links for each lot, so the coordinates have to be pretty tight and spot on. 

Hi,

I'm not seeing any example code or demo of the issue you're having. Could you attach a screenshot or live demo, please?

Thanks,

Dan