Use a measuring tape to measure the trailer from end to end. Include the bumper in the measurement, as well as anything that sticks out, like a bike rack, ladder or spare tire.
Measure the height of the trailer. Do not add in the air conditioner to the overall height. The standard trailer cover accommodates air conditioners.
Measure the trailer skirt length if you would like a longer tarpaulin cover. If not, omit the trailer skirt length.
Measure the trailer width.
Use these measurements when purchasing your trailer cover.