CGT payable?

I cannot say for certain, but I would guess that the value after you moved out is the portion that would go toward CGT, check with an accountant or wait for a response from someone who knows for certain.

Remember to add other items to reduce the CG, a good tax accountant when it comes time to pay your dues will be important, costs such as capital improvements (installing a new room or garden extra garage etc) all go towards that, as well as stamp duty and any other costs that are not tax deductible (building/pest reports etc) these all lower the amount of CGT payable, of course they would have to be apportioned to the % of time lived and time rented.  A true capital gain is only what you have actually made on the property after everything you have spend on the place. Again spending extra cash on a knowledgeable accountant verse a $50 tax guy at your local Westfields will pay dividends here (not saying you use these type of people but just pointing it out).

You are correct, you can't use the 6yr rule if you are claiming the current property as your PPOR. Has that had any CG? If not leave the first one as your PPOR.

Yes basically    $500K – $465K = $35K is your capital gain. But you deduct buy costs, sell costs etc,  then multiply by 50%?

So by the time you take out stamp duty ($18K if in NSW) and other costs, then halve it you won't have a high CG. I think you apportion the buying costs to the time it was an IP.

But then you add that to your income. So you can reduce the amount you pay in other ways too. EG Take some time off without pay, salary sacrifice some of your income to super in the year you sell etc.

Not to mention that an agents valuation can often be optimistic and more than a real valuation, they may quote at 10-20k above what a real value is, meaning you pay more CGT..