Can a pork roast with mass of 18 grams feed family four?

No way! An 18-gram pork roast is incredibly tiny, probably smaller than a single bite.

To feed a family of four, you'd need a pork roast significantly larger, likely in the range of several pounds (around 2-4 kg).

Here's a rough guide for planning a pork roast:

* Small family (2-3 people): 1-2 pounds (0.5-1 kg)

* Medium family (4-5 people): 3-4 pounds (1.5-2 kg)

* Large family (6+ people): 4-6 pounds (2-3 kg)

Keep in mind these are just estimates, and you might need more or less depending on appetites and other dishes served.