The ingame fitting tool is great, you get a rough EHP and are told your HP/s from your active tank. That being said I was more curious about my EHP per damage type and my EHP/s that my active tank gives me. I made this Sheet that calculates both. Better helping me see how the holes in my resistance really affect me and where my tank shines. Being that the EHP/s is also calculated per damage type I can also see how my active tank can match up for every damage type. I include an average and worst/best case Colum for quick referencing .
Feel free to copy into your own sheet so you can edit it and see how your tank does