Emooooz have two postures. Here is one, 'normal horizontal' (The bird is Felicity. If you google just 'Felicity Emu,' half of the photos that come up are my place: she is famous):
Here is the other, 'upright' (This is Felicity's famous sister, 'Greedy,' now feared dead.):
In the upright mode, an adult is almost six feet tall.
But they can jump much higher than captive-bird owners would probably guess. I saw Greedy, a 'double-alpha' bird, with the top of her head certainly nine feet off the ground as she landed the two-footed kick to her dad's chest that brought her her dad's crown, control of the house-clearing pasture.
Adult birds -- for example, during the fig season here -- can often be seen stretching up/jumping up to score juicy figs and other tit bits. On tippy toes, about six feet six.