What is the telephone area code for Calgary Canada?

The area code for Edmonton and northern Alberta is +1 780. Area code +1 587 is an overlay for the entire province.

(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but Japan uses 010, Australia uses 0011, and many other countries use different prefixes.)