Over in EU there are of STANDARDS for these things, kitchen measures come in sets,
1 tsp = 5ml
1 tblsp = 15 ml
and one smaller which I call a pinch = 1ml

I have tested several og these kits, steel, plastic and from various sources, IKEA has a plastic kit that can be found in most of the "civilized world", they are all surpricingly accurate, and MORE than good enough for mixing Kaffenol...........

Other than that I'm a convined gram/ml guy and only offered this conversion table for those that wanna go from the mysterious US recipes to metric.....