The better question is how tall isn't the Rev Roof Top Tent?
Because the Rev Roof Top Tent is modular, you can easily adjust the tent height on the vehicle. What we mean is: you don't HAVE to stack everything together for transport if you have height limitations.
The Rev Platform closed is 3.75", the Rev Tent closed is 8", and the ladder is 3"
Stacked all together it's 14.75" off your load bars or roof rack. Store the ladder in your vehicle - you're at 11.75"; store the tent in your vehicle - you only have the 3.75" height of the Rev Platform added to your load bars.
If you're height challenged with a garage door, one person can quickly remove the Rev Tent and Ladder after a camping trip (by quick, less than a minute) and problem solved.