Might be a daft question (wouldn’t be the first on here!) but how do you work out the overall height of your vehicle with so many different types of cars and vans carried?
Tin 'at on!!
A measuring stick
Excellent…thanks 
Most trailers have the running height on the headboard, so along as the unit is a standard unit then it will be roughly what it says on the trailer/truck
mark h:
Most trailers have the running height on the headboard, so along as the unit is a standard unit then it will be roughly what it says on the trailer/truck
Think the op was on about a car transporter trailers and how to measure the height with different size vehicles on the top deck.