The amount of tax you will pay on the income from your sole trader business will depend on how much you earn from your annual wages.

For a sole trader, your business income will add to your wages income and you will pay tax at your marginal tax rate.

For 2017-2018 theindividual marginal tax rates are:
$0-18,200 Nil Tax
$18,201 - $37,000 Tax - 19c for every dollar over $18,200
$37,001 - $87,000 Tax - $3,572 plus 32.5c for every dollar over $37,000
$87,001 - $180,000 Tax - $19,822 plus 37c for every dollar over $87,000
$180,001 and over Tax - $54,232 plus 45c for every dollar over $180,000

These do not include the 2% medicare levy. You will need to pay an additional 2% on your total taxable income for the medicare levy.

An example would be if you earn $50,000 from wages and $12,000 from your business, the additional tax on your business income would be $3,900 plus $240 medicare levy. This is because you fall in the 32.5c marginal tax bracket.  

As a salary and wage earner, your employer should be withholding the appropriate amount of tax and medicare levy from your wage to cover the tax on the $50,000.