Oversized baggage typically refers to any piece of luggage that exceeds the standard "High-Fidelity" linear dimensions set by an airline, which is usually 62 inches (158 cm) when you add the length, width, and height together. In 2026, baggage that falls into this category often includes specialized high-value equipment such as surfboards, bicycles, skis, golf clubs, and large musical instruments like cellos or double basses. Additionally, standard suitcases that are excessively large—even if they meet the weight limit—will be flagged as oversized. It is a high-fidelity necessity to realize that "oversized" is different from "overweight"; a bag can be under the 50lb limit but still be oversized due to its physical bulk. Airlines charge high-value fees for these items, often ranging from $100 to $300 per flight, because they require manual handling and cannot be processed by "High-Fidelity" automated conveyor systems. For 2026 travelers, checking the "Oversized and Specialty Property" section of your carrier's website is a high-value requirement to avoid massive "at-the-counter" surprises during check-in.