My mat is 32 inches in diameter.
By the way, while I provided a link to the Cellersize rebounder, after watching the video that records a very noisy Bellicon with bungees, I found that it strains belief.
You should think about the noise with respect to your housemates, however. They may become irritated by this repetitive noise. If you can shut a door and insulate the sound from the rest of the house, then that could help.