If the answer above is None it means there is no specific mention in the legislation, but you still need to ask local law enforcement before drinking in Netherlands.
The legal age for purchase and consumption of alcohol beverages was raised from 16 to 18 in 2014. Selling alcohol beverages to people under 18 is prohibited, buying alcohol beverages for someone else under the age of 18 is also prohibited.
You can find more legal details and links here:
Wikipedia Legal Drinking Page