Workers paid bi-weekly should receive 26 pay checks in a year. This is based on the fact that there are 52 weeks in a year.
In order to calculate the number of pay periods in a year, you divide the number of weeks in a year (52) by the frequency of payroll payments. Fifty-two divided by two equals 26. This figure may be adjusted to compute for unpaid vacation time. For a worker who receives two weeks of unpaid vacation, the equation changes. Subtract the unpaid weeks from the total number of weeks in a year, and divide that number by the payroll frequency. Your answer would then be computed by dividing 50 by two, giving you 25 pay checks per year.