It depends on the type of epoxy you are talking about. If you are considering the commercially installed oil based coatings, that type of epoxy coating is about the toughest you can get.
If you are considering the DIY owner installed two part epoxy coatings that you get from Home Depot, which is marketed by companies such as Rustoleum and Quikrete, it isn't nearly as tough. I would gauge it as maybe 2-3 times stronger than garage floor paint.
After only 4 years, I can now see bare concrete under the area where my rolling bench chair is because the epoxy is wearing off. I have dropped and scraped a number of things on the floor that has removed the coating. And just this past winter I spilled some brake fluid on the floor that I didn't notice for about 2 hours. It dulled the finish badly, but didn't bubble the coating. (paint would have lifted.)
I had slim hopes that it would hold up, but it didn't. No big deal. It only cost me $50 and half a day. Sometime this year I am going to install commercial vinyl tile.
Whatever you do, unless you are a masochist, don't use the speckles like I did. Drop a screw on the floor, and it is gone forever. Solid colors or patterns only.