Hey everyone. First, I must say I hate this bathroom. All my other bathrooms are marble floors with nice vanitys, but this is how this one was when I moved in.

I will be REPLACING the floor and the vanity. I never liked how close the toilet was to the vanity. There is the vanity, the toilet, and then a shower which is like 4 feet away from the toilet! It just looks strange.

So, I want to move the toilet down to the left some. Now, if the floor joists are running this way --------- can this be done? Is this a huge deal?
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I can't stand how the door or the right blocks the vanity, so want to put the new vanity more to the left, and the toilet will need to go to the left as well.

Sure it can be done. Remove toilet, cut sub-floor, set new closet ring where you want it and connect with existing toilet drain. You can cut through couple of floor joists if you have to. But, do not butcher it. Drill nice hole to fit just the pipe. Best is to use Milwaukee drill bits. They make drill for every size/type of pipe.