11 t24,300 lb
A full-size American school bus weighs around 11 tonnes (24,250 lb) empty, which is the weight of a large diesel bus that seats 66 to 90 children. Smaller conventional buses come in lighter, and battery-electric ones are heavier: one 2023 model lists 14,440 kg (31,835 lb). The biggest buses are rated for up to 16,420 kg (36,200 lb) fully loaded.
| Largest bus, fully loadedIts 36,200 lb weight rating, Blue Bird All American with up to 90 seats | 16.4 t36,200 lb |
|---|---|
| Battery-electric bus, emptyCurb weight on BYD’s 2023 Type C spec sheet, 288.8 kWh battery | 14.4 t31,800 lb |
| Heaviest a 90-seat bus can be empty36,200 lb rating minus the federal occupant allowance | 11.5 t25,200 lb |
| Large full-size bus, emptyThe figure on this page | 11 t24,300 lb |
| Heaviest a 78-seat conventional bus can be empty33,000 lb rating minus the federal occupant allowance | 10.7 t23,500 lb |
Bus makers rarely print an empty weight. What they publish is the gross vehicle weight rating (GVWR), the most the loaded bus may weigh. A federal rule, 49 CFR 567.4, says the GVWR must be at least the empty weight plus 120 lb (54 kg) for every passenger seat and 150 lb for the driver. So the rating puts a ceiling on how heavy the empty bus can be.
The biggest transit-style buses, such as the Blue Bird All American, seat up to 90 and are rated up to 36,200 lb. The occupant allowance is 90 × 120 + 150 = 10,950 lb, which leaves at most 25,250 lb (about 11.5 t) for the bus itself. A 78-seat conventional bus with the common 33,000 lb rating gets 78 × 120 + 150 = 9,510 lb of allowance, so it can weigh no more than 23,490 lb (about 10.7 t) empty.
A bus can come in under its ceiling but not over it, so 11 tonnes describes a big bus, not an average one. Shorter buses with fewer rows and lower ratings weigh less.
In the US and Canada, school buses are sorted into four types. Types A and B are the small “short buses”. Type C, the conventional bus with a hood in front, is built on a medium-duty truck chassis and is the most common design. Type D is the flat-fronted transit-style bus, the largest of the four, with the engine at the front or the back.
Full-size buses usually carry 66 to 90 passengers, and bodies are limited to 45 ft (13.7 m) long and 102 in (2.59 m) wide. Typical ratings: the Blue Bird Vision goes up to 33,000 lb, the IC Bus CE Series 19,500 to 33,000 lb, and the Thomas Saf-T-Liner C2, which sits on a chassis derived from the Freightliner M2 truck, 18,000 to 35,000 lb depending on length.
Batteries add a lot of weight. BYD’s spec sheet for its Type C electric bus lists a curb weight of 31,835 lb (14,440 kg) with a 288.8 kWh battery and a 35,000 lb rating, about 3.4 tonnes more than the figure on this page.
Other electric buses come with smaller packs. The Lion C offers 126, 168 or 210 kWh and is rated up to 31,000 lb, and the electric IC CE Series comes with 105, 210 or 315 kWh, good for over 70, 130 or 200 miles.
A NHTSA research paper on large school buses says they protect their passengers “because of their visibility, size, and weight” compared with other vehicles. Inside, the main protection is compartmentalization: padded seat backs 28 in (71 cm) high, spaced no more than 24 in (61 cm) apart, so a child is held in a small padded box rather than by a belt. Federal rules require seat belts only on small buses with a GVWR under 10,000 lb.
In one NHTSA side-impact test, a 11,406 kg (25,265 lb) cab-over truck was towed at 72.4 km/h (45 mph) into the side of a parked transit-style school bus. That truck weighed about as much as the 11 tonnes on this page. It pushed about halfway into the passenger compartment, and the front axles were torn off both vehicles.
A large full-size school bus weighs around 24,250 lb (11 t) empty. The biggest ones are rated for up to 36,200 lb when fully loaded.
The federal rules count 120 lb per passenger, so a full 90-seat bus is allowed 10,800 lb of children plus 150 lb for the driver. That takes a big bus from about 25,000 lb empty to as much as 36,200 lb.
The color was picked at a 1939 conference organized by Frank W. Cyr of Teachers College, Columbia University, because black lettering on it was easy to read in semi-darkness and it stood out at a distance. It is now called National School Bus Glossy Yellow, Federal Standard 595a color 13432.
Yes, because of the battery. One electric Type C bus lists a curb weight of 31,835 lb (14,440 kg), several tonnes more than a large diesel bus.
A full-size bus is usually about 26 to 42 ft long; the Blue Bird Vision, for example, comes in 7.8 to 12.7 m. US and Canadian rules cap school bus bodies at 45 ft (13.7 m).
Last checked October 2, 2026.
