The golden ratio for home theater design is widely considered to be H (Height) x 1.28H (Width) x 1.54H (Length/Depth). For example, if you have a room that has a 10ft ceiling height, the ideal width and height would be 12.8ft and 15.4ft respectively.

While there's no minimum room size required, a room that's at least 15 feet wide and 20 feet long is a good starting point when building your home theater. It also ensures you have enough extra space for standard theater equipment as well as optional furniture pieces like an A/V rack, bar, or an extra table.

Here are some ratios you can use to get your room to a great basic shape. Get somewhere between a ratio of 1 to 1.6 or 1.7 and 2.3 to 2.4, you will be well on your way to an ideal home theatre layout. As an example, if you went 1 to 1.6 to 2.4, a room with a 10' high ceiling would be 16' wide and 24' long.