The calculation explains my first example as well as your example with flex-basis: 0;.. By the way, as we’re working on the x-axis in this example, we are actually setting the (initial) width with flex-basis. “Easy,” I thought. So can't give fixed height. #parent { display: flex ... .not-equal { align-self: flex-start; } However, it took me less then 5 minutes to find the answer (and I … The