If you allow too much tax to be withheld, you get a refund. You can determine how much is tax is taken out of your pay by the number of allowances you claim on your W-4. The W-4 has a worksheet to help you figure out how many personal allowances to take.
Step 5: Predict your next period. Now that we know how long your period cycle is, we can just use it to count the days to predict your next period. My period cycle is 28 days so if I count 28 days from February 10, that's when my next period should come.
In order to use this calculator, you must know either the first day of the last menstrual period or the due date. as calculated by your health provider. Select either the First Day of Last Menstrual Period or the Due Date. 1  Enter the date (corresponding to what you selected above, either the First Day of Last Menstrual Period or the Due Date). 2  Push the Calculate Dates button. (Note: Scroll down to see your results).