Cook Islands 2010 1 cent KM#756 - wrong size?

I was searching for my smallest coin and according to Numista, this coin is 11.8mm small. But when I took it out of the album to take a look it looks quite a bit bigger.



Looks to me like it is about 17mm. (Don't want to take it out of the flip to do exact measurement.)

Also, the weight seems to be about right. One flip with 3 staples is 2.66g (a slightly different flip though) and coin in its flip is 6.06g so mine is 3.4g (with a marginal error) vs 3.64g in the catalog.

Does anybody know what the right size is?

Speaking of size errors...

Here is another one - Denmark 1818 2 Rigsbankskilling. Is it really 3.1mm in diameter and 3mm think? Can't even imagine what it'd look like.  

changed to 17mm. I will let the weight as it is - as for now.
thanks