Hi Chris,
My Chefs spoon = 50ml (level spoonful) = about 3 tblsp - 2 chefs spoons = 1 ladle
Those are my direct measurements though, one Stainless Ladle I have is 100ml, and a Wok set ladle held 115ml.
Not sure how much Chefs/Serving Spoons vary (not much I think), but Ladles do come in various sizes.
Hope that helps
Martin