What is my IP country?

Based on your IP (54.163.42.154), your country is United States


How do we know that?

Specific ranges of IP address numbers are allocated to each country. For instance, IPs from 54.240.0.0 to 54.255.255.255 are used by the United States, and IP addresses from 109.208.0.0 to 109.223.255.255 are used by France.
So unless you're masking your real IP (with a proxy, a VPN, etc.), since your IP is public, your country is known too.