Calculating eligibility for EI is a fluid process because it is based on a number of variables including number of hours/weeks worked, pay rate, regional unemployment rate, EI history etc.

Service Canada says:

• Benefits are calculated using your “best weeks” of gross earnings (see below) during the qualifying period.
• The qualifying period can vary. The minimum is determined by regional unemployment and the maximum is the previous 52 weeks.
• Once the best weeks divisor is determined your total earnings are divided to obtain an average.
• Benefits are calculated at 55% of this amount up to a maximum amount of $524/week.