Place the luggage on a flat surface
Measure the height from the bottom to the highest point, including wheels and handles if they are fixed
Measure the width across the widest part
Measure the depth from the front to the back at the deepest point
Add the height, width, and depth together to get the total size
Check the airline’s specific size rules before traveling
Use a tape measure for accuracy
Measure with all external pockets and attachments included if the airline counts them