Estimate weight of a school bus

I can help here a bit.

We'll assume that the bus is average length (65 passenger). For calculation, I'm using a 1991 Wayne bus on an International chassis. More specifically, this exact bus:


If we look at the GVWR tag, for this bus it is 23,500#. That's the most that the bus could legally cross a scale at. Obviously Wayne would leave some wiggle room for weight, but we'll just calculate backwards.

65 passengers is three to a seat. We'll say that each kiddo weighs 100 pounds. That's 6500 pounds. Subtract that from the GVWR (23,500#), and we're left with 17000 pounds. We'll say that the driver weighs 250 pounds (He's kind of big like me!), bringing us to 16,750 maximum body weight.

We'll assume that the bus has a 60 gallon diesel tank (We'll say that it's a diesel school bus). Diesel weight can vary, but we'll go with 7.5 pounds per gallon. 60 gallons (A full tank) would weigh 450 pounds, excluding tank weight. So, subtract that, and we're left with a maximum bus weight of 16,300 pounds.

You said that tires were gone. An 11R22.5 tire (Common school bus size) will weigh around 125 pounds (Data Sheet). Multiplied by 6, that's 750 pounds (Not counting rims). Subtract again, and we're down to 15,550 pounds. That's the most the bus can weigh. It'll weigh less, because the seats and roof are removed.

Seating configuration will vary based on the body manufacturer. We don't know the length of the bus either, so I used an "average" length for the period. A longer bus will weigh more.

What we do know is that a 1991 Wayne school bus that's rated for 65 passengers plus driver, cannot weigh any more than 15,550 pounds. The body will actually weigh less, because the seats and roof have been removed, and we didn't account for them.