I don’t know, I haven’t weighed them. My girls are just over a year old now and the eggs got bigger as time went by, just like chickens. Runner eggs are typically about the size of a jumbo chicken egg from what I’ve read, and I’d say that’s about right, maybe a little bigger.@igorsMistress What's the average weight on the runner duck egg's? I have some of those Welsh Harlequin duck egg's that I'm hatching. Those are huge, but so are these Bielefelder hatching egg's I'll be hatching out on the 17th for the due date.