This calculator allows you to calculate your estimated rate of payroll tax.

The rate is based on annualised wages. e.g. If you employ for only 150 days in the year and the wages paid during that period is $630 000, your annualised wages total would be calculated as follows:
$630 000 divided by 150 then multiplied by 365 or 366 days. Your annualised wages would therefore be $1 533 000.