Paycheck 2021 determines your paycheck’s net pay by calculating Federal and State taxes and taking into account Pre and Post Tax deductions. Paycheck 2021 includes your tax filing status, your expected income adjustments and your expected itemizations to lead you through the complicated 2021 W-4. Paycheck 2021 allows you to enter up to 4 paychecks and compare the expected withholding of each paycheck to the calculated income taxes to determine the expected tax bill or refund at the end of the year.