To calculate linear inches, simply determine the length, width and height of a baggage item and add them together. You need a tape measure or ruler and a calculator.

**Measure the length, width and height of the luggage**Using a tape measure or ruler, measure the length, width and height of the outside of the luggage in inches. Include objects such as wheels and outer compartments when measuring.

**Find the sum of the three measurements**Using a calculator, add the length, width and height together. The total is the linear inches measurement of the luggage.

**Know your limits and fees**Linear inches are used in the travel industry to impose restrictions for carry-on and checked luggage. Find out about any restrictions and additional fees in advance.