Hello all! Long time no post. :)

I'm making my sister in laws wedding cake this weekend, as a gift. She wants a 4-tier alternating round and square cake. Really simple design. My only concern is stacking the appropriate sized cakes. I've never stacked square on round. I did a little googling, a little surfing these forums, and a little math and came up with 16" round, 11" square, 9" round and 6" square. That will cover her request for about 150 servings plus leave her the top tier. I'm now doubting my math and google results. I have stacked my pans and sps plates and they all fit, but I just cant visualize it in cake form. I'm afraid maybe I should go with a 10" round instead of 9"? I really don't know. It would ease my mind to see a stacked cake with those sized tiers, so I could see what the proportions will actually be. It's coming down to crunch time - I'm baking - so now I'm just letting my anxiety get to me. I've only done one other wedding cake, and it was all rounds. No brainer! If anyone has any input on it, I would gladly welcome it. Are these tier sizes appropriate for an evenly-proportioned look?

I appreciate any response, and please forgive any typos. I'm wearing false nails because I'm also a bridesmaid, and I can barely function with them.

If my math is correct, it serves 184/202.
 

AI use earlenes chart, which gives me 162 without the top tier. As close as I could get without being under. I just want someone who has stacked these sizes or can visualize it to ease my mind...is this going to be proportionate? I can't see a finished product in my head.