Weird sized motherboard

[Elmex]

Hi, I bought a Gigabyte B450M DS3H motherboard last year. I have been using it ever since. Recently I got an idea to make a pc case that would be easy to carry around and bring with me where ever I go. Since I like to tinker I wanted to make the case myself. I want to move my current rig to the new case since I don't have the money to buy a second computer. I found measurements for mATX (picture below). After finishing the design of the case I had a clever idea to check if my motherboard would actually fit in the case. It didn't (the outer most mounting holes would be outside the case edge) even though it is being sold as an mATX motherboard. I noticed that for some reason my motherboard is only 244mm x 215 mm instead of 244mm x 244mm. I have not been able to find exact measurements for my motherboard and I do not have the tools to measure them on my own. Does anyone know what the exact measurements for this type of motherboard are or where I could find them? Specifically, I am looking for positions of mounting holes. (Motherboard: Gigabyte B450M DS3H)

Picture is from Protocase: https://www.protocase.com/resources/how-to-design-for-motherboards/

Link to the motherboard in Amazon: https://www.amazon.com/GIGABYTE-B450M-DS3H-Ryzen-Motherboard/dp/B07FWVJSHC

Link to the motherboard manufacturers site: https://www.gigabyte.com/Motherboard/B450M-DS3H-rev-10#kf

 

PS.

English is my second language so I apologize for any mistakes.

[Jurrunio]

It is normal for some boards to be smaller than advertised. Extra PCB costs money after all.

[Windows7ge]

So you don't own a tape measure or a ruler?

 

Instead of trying to source measurements that have to be fairly precise here why not just pull out your motherboard, put it on the sheet of whatever material you're using and mark though the motherboard holes where you need to drill the mounting holes? I think it'd be a lot faster/easier since I believe you'll be hard pressed to find anyone here with your motherboard who can also give you those precise measurements.