Google’s answers refer mostly to Dungeons & Dragons, where the dragons weigh tons, and that’s not my fantasy universe. I want a fantasyland closer to our consensus reality (the “real world” to Muggles). Dragons fly, and birds fly, so perhaps we could extrapolate dragon weight from bird weight.
Canada geese have a sort of dragon-like shape — and like dragons, they can be nasty. If geese could spit fire at us, I’m sure they would. Very roughly (for easy math) a Canada goose is 3 feet long from beak to tail, has a 5 foot wingspan, and weighs 10 pounds. A dragon 30 feet long with a 50 foot wingspan would weigh 100 pounds.
That’s not very much. It would be far easier to carry around a dog-sized dragon than to carry around an actual dog. The hard part would be avoiding the dragon’s fiery breath.
Even a dragon the length of a city block, about 300 feet, with a wingspan equal to the height of a 50-story building would weigh only 1000 pounds. A dairy cow weighs more. World champion weightlifters could pick up a skyscraper-sized dragon.
So ... dragons are lightweights. That’s useful to know.
-- Sue Burke