How to properly measure your luggage (and the surprising reason you should)

You really don't want to trek all the way to your airport gate only to find out that your carry-on suitcase doesn't meet the height requirement or that your checked luggage is just a little too big. "Even being one inch over airline limits can result in unexpected gate check fees or oversized baggage charges," says Vita Musacchia, design director at Roam Luggage.

The easiest way to avoid this nightmare scenario is to measure your  luggage  before your trip. Here's how experts say it should be done, along with tips for getting the most accurate measurements.

How to measure your luggage

1. Grab your tools

All you'll need is a measuring tape and a level, which helps minimize the risk of miscalculations from uneven surfaces. It's not a total deal breaker if you don't have one, but it does help — you can even use a piece of cardboard in a pinch.

2. Set up properly

• Make sure the bag is completely zipped up.If you'll be traveling with the bag expanded, measure it that way.

• Place the suitcase on the floor.Getting a level measurement from a flat surface is crucial. "When we test luggage, all measurements are taken from the ground up," says Senior Style Editor and resident luggage-testing expert, Jessica Teich . "It minimizes room for error, especially for protrusions like wheels and handles."

• Don't forget the wheels and handles.The body of the suitcase isn't actually the measurement airlines care about. Bag size restrictions usually "are for the entirety of the suitcase from its tallest and longest points, usually from helper handles to wheels," Teich explains.

3. Measure the length from floor to level

Teich says to set the suitcase on its side, helper handle or feet and place your level on the opposite side at its tallest point, "which is oftentimes a reinforced edge, handle or protruding zipper." Then, measure from the floor to the level. "Measure directly across the suitcase at its widest points, accounting for any protruding zippers or helper handles," Teich says. 

4. Measure the width from front to back

For the width/depth of the bag, Teich says, "lay the suitcase down flat on its back and run the tape measure along the width to the widest part of the front, oftentimes the bowed apex of the bag, a front pocket or a seam/ridge in the design."

5. Measure the height from the wheels to the top handle

"Set the suitcase upright on its wheels and use a level on the top handle; measure from floor to level," Teich says. 

6. Calculate the total linear inches

While the above steps will provide you with L x W x H measurements, most airlines also calculate bag requirements using linear inches, which is the sum of a bag's length, width and height. Add your final measurements together to calculate the total linear inches. "For example, a bag measuring 28" x 18" x 14" equals 60 linear inches," says Musacchia.

Common domestic airline luggage size requirements

Musacchia says that the standard carry-on dimensions for most domestic airlines are 22" x 14" x 9" (45 linear inches), and for checked luggage , 62 linear inches. These are the bag size restrictions (in linear inches) for some of the most popular major domestic airlines in the U.S.:

Luggage measuring tips

Double-check the listed manufacturer dimensions

Manufacturers include dimensions with their luggage, but it's worth double-checking them yourself. Teich says that during luggage testing , her team's measurements don't always align with manufacturers' because some brands list only the dimensions of the packable case.

"We've found on numerous occasions that some luggage brands list only the dimensions of the packable case," she says. "Not considering those extra few inches from the handles and wheels can make the difference between a suitcase that fits in the overhead and one that's checked at the gate."

Measure your suitcase when it's both empty and packed

A baseline measurement is helpful but you won't be bringing an empty suitcase with you to the airport. More than likely, it'll be jam-packed with everything you can fit in there. Taking the time to measure your bag again once it's packed will give you a more realistic view. 

"If you're anything like me and have a tendency to stuff your bag to its brim, remember that even hard-side luggage can bulge when fully-packed, which is why it's important to measure your bag once it's all packed up and ready to go," Teich says.

Choose the right carry-on

Opt for the most reliable, space-friendly checked luggage