As of September 2009, Northwest allows each person to carry two total items aboard their flight. The first can be a smaller suitcase or laptop bag. The second can be a personal item such as a purse or backpack. Bags you carry on must be small enough to fit into the overhead compartment on the airplane or beneath the seat in front of you.
If you are traveling with any liquid or gel items but aren't checking in any bags, you must separate those items into a quart-sized ziploc bag. Each of these items must contain no more than 3 fluid ounces. Also, the ziploc containing your liquid items must be fed through the conveyor belt separate from your other bags during the security check.
If you need to check in your luggage during your next trip, be prepared to shell out a minimum of $15. It will cost you an additional $25 if you check a second bag. If you pay checked bag fees online, you will be charged solely for the cost of each bag. However, if you decide to check your luggage at the airport, you will be charged an additional $5 per bag you check in.
Each bag you plan to check in must not weigh more than 50 pounds. Because scales are calibrated differently, the weight of your bag may be different on your own scale than the one used at the airport. If you keep each of your bags weighing between 40 to 45 pounds on your own scale, it will ensure that you do not exceed 50 pounds on the airport scale.
In addition to weight, Northwest Airlines also sets a maximum limit for how large your bag can be. The total height, length and width for each of your bags may not be more than 62 inches.
Depending on your final destination, if you are traveling to a location outside the United States, you are allowed to check either one or two bags free of charge. Restrictions on total weight and dimensions for each bag remain the same as domestic travel.
If you are a member of either the Northwest Airlines WorldPerks Elite or Delta SkyMiles Medallion programs, you are allowed to check in two bags free of charge per domestic flight and up to three bags for international flights. Each of your checked bags must weigh in at 70 pounds or under, though dimensions of each bag must still total 62 inches.
