RV measurement can be done in a few different ways, but the most common and accurate way is by using a laser measuring device. This type of device will measure the length, width, and height of your RV with great accuracy. You can also use a tape measure to get approximate measurements, but these can be less accurate. When measuring your RV, you will need to take into account any slide-outs or other additions that may add to the overall length or width of the vehicle.