Not sure if anyone can help me.
I have been playing around with the look of our finances etc just to make sure everything looks ok and well, I am totally confused about Tax.

So, basically I have three sources of income.
I took the Jul-Sep quarter total for these incomes, and multiplied by 4 to get myself an adjusted estimate of income.
Also I have multipled the tax withheld as this should total tax withholdings at the EOFY, right?

But then... I am looking at how much tax one should pay. It says $4650 up to $37000 and 30c per dollar thereafter.
And so I used that to work out that - for example, and income of $70k should pay $9900 + that $4650 previously mentioned.
= tax to bed paid $14550.

But my multiplied numbers equal some thousands less than they should. So I don't get it???
I checked the tax tables per each source to make sure I am getting taxed correctly so I am not really sure how it works out to be wrong =/

Can someone enlighten me I know I am overanalysing and I can get my employers to withhold more and then offsets might work out anyway but I'm stressing about having a debt.